78538696931 has 4 divisors (see below), whose sum is σ = 78665988792. Its totient is φ = 78411405072.

The previous prime is 78538696861. The next prime is 78538696991. The reversal of 78538696931 is 13969683587.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 78538696931 - 2²⁶ = 78471588067 is a prime.

It is a super-2 number, since 2×78538696931² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78538696991) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63645005 + ... + 63646238.

It is an arithmetic number, because the mean of its divisors is an integer number (19666497198).

Almost surely, 2^78538696931 is an apocalyptic number.

78538696931 is a deficient number, since it is larger than the sum of its proper divisors (127291861).

78538696931 is a wasteful number, since it uses less digits than its factorization.

78538696931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127291860.

The product of its digits is 58786560, while the sum is 65.

The spelling of 78538696931 in words is "seventy-eight billion, five hundred thirty-eight million, six hundred ninety-six thousand, nine hundred thirty-one".