# 142 (number)

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 ← 141 142 143 →
Cardinal one hundred forty-two
Ordinal 142nd
(one hundred forty-second)
Factorization 2 × 71
Divisors 1, 2, 71, 142
Greek numeral ΡΜΒ´
Roman numeral CXLII
Binary 100011102
Ternary 120213
Quaternary 20324
Quinary 10325
Senary 3546
Octal 2168
Duodecimal BA12
Hexadecimal 8E16
Vigesimal 7220
Base 36 3Y36

142 (one hundred [and] forty-two) is the natural number following 141 and preceding 143.

## In mathematics

There is no answer to the equation φ(x) = 142, making 142 a nontotient. There are 142 planar graphs with 6 unlabeled vertices.[1]

${\displaystyle {\frac {142^{1231}-1}{141}}}$ is the smallest repunit prime in base 142, it has 2648 digits, while the smallest repunit prime in negative base -142 is only 20023. Besides, the smallest Fermat prime in base 142 is 406586897, and the smallest Wieferich prime in base 142 is 143111.

## References

1. ^ Erich Friedman, "What's Special About This Number": 142. Accessed 5 JAN 2008.