Number of the day: 167

Richard K. Guy was born on this day 104 years ago.

Properties of the number 167:

167 is a cyclic number.
167 is the 39^th prime.
167 has 7 antidivisors and 166 totatives.
167 has a semiprime digit sum 14 in base 10.
167 has a sphenic digit product 42 in base 10.
167 has an oblong digit product 42 in base 10.
Reversing the decimal digits of 167 results in an emirp.
167 = 84² - 83² is the difference of 2 nonnegative squares in 1 way.
167 is the difference of 2 positive pentagonal numbers in 1 way.
167 is not the sum of 3 positive squares.
167² is the sum of 3 positive squares.
167 is a proper divisor of 1669² - 1.
167 is an emirp in (at least) the following bases: 2, 3, 5, 7, 10, 12, 14, 15, 19, 22, 25, 28, 29, 32, 33, 39, 41, 43, 44, 49, 50, 55, 57, 67, 69, 71, 75, 85, 86, 87, 91, 93, 94, 95, 97, 98, 99, and 100.
167 is palindromic in (at least) the following bases: -6, -11, and -83.
167 in base 12 = 11b and consists of only the digits '1' and 'b'.

The number 167 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A000040: The prime numbers.
A000837: Number of partitions of n into relatively prime parts. Also aperiodic partitions.
A000961: Powers of primes. Alternatively, 1 and the prime powers (p^k, p prime, k >= 1).
A002145: Primes of the form 4*k+3.
A004767: a(n) = 4*n + 3.
A005385: Safe primes p: (p-1)/2 is also prime.
A006567: Emirps (primes whose reversal is a different prime).
A008578: Prime numbers at the beginning of the 20th century (today 1 is no longer regarded as a prime).
A050376: "Fermi-Dirac primes": numbers of the form p^(2^k) where p is prime and k >= 0.
A065091: Odd primes.