78863931 has 18 divisors (see below), whose sum is σ = 115187540. Its totient is φ = 51994800.

The previous prime is 78863923. The next prime is 78863933. The reversal of 78863931 is 13936887.

It is a happy number.

78863931 is a `hidden beast` number, since 7 + 8 + 8 + 639 + 3 + 1 = 666.

It is not a de Polignac number, because 78863931 - 2³ = 78863923 is a prime.

It is a super-2 number, since 2×78863931² = 12439039225545522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78863933) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 91380 + ... + 92238.

Almost surely, 2^78863931 is an apocalyptic number.

78863931 is a deficient number, since it is larger than the sum of its proper divisors (36323609).

78863931 is a wasteful number, since it uses less digits than its factorization.

78863931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1067 (or 963 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 78863931 is about 8880.5366391902. The cubic root of 78863931 is about 428.8375507644.

The spelling of 78863931 in words is "seventy-eight million, eight hundred sixty-three thousand, nine hundred thirty-one".