78945531 has 16 divisors (see below), whose sum is σ = 123550464. Its totient is φ = 43892064.

The previous prime is 78945527. The next prime is 78945547. The reversal of 78945531 is 13554987.

It is not a de Polignac number, because 78945531 - 2² = 78945527 is a prime.

It is a super-2 number, since 2×78945531² = 12464793729743922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78945521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50025 + ... + 51578.

It is an arithmetic number, because the mean of its divisors is an integer number (7721904).

Almost surely, 2^78945531 is an apocalyptic number.

78945531 is a deficient number, since it is larger than the sum of its proper divisors (44604933).

78945531 is a wasteful number, since it uses less digits than its factorization.

78945531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101650.

The product of its digits is 151200, while the sum is 42.

The square root of 78945531 is about 8885.1297683264. The cubic root of 78945531 is about 428.9854049294.

The spelling of 78945531 in words is "seventy-eight million, nine hundred forty-five thousand, five hundred thirty-one".