78656631 has 4 divisors (see below), whose sum is σ = 104875512. Its totient is φ = 52437752.

The previous prime is 78656629. The next prime is 78656681. The reversal of 78656631 is 13665687.

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 78656631 - 2¹ = 78656629 is a prime.

It is a super-2 number, since 2×78656631² = 12373731200540322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78656681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13109436 + ... + 13109441.

It is an arithmetic number, because the mean of its divisors is an integer number (26218878).

Almost surely, 2^78656631 is an apocalyptic number.

78656631 is a deficient number, since it is larger than the sum of its proper divisors (26218881).

78656631 is a wasteful number, since it uses less digits than its factorization.

78656631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26218880.

The product of its digits is 181440, while the sum is 42.

The square root of 78656631 is about 8868.8573672148. The cubic root of 78656631 is about 428.4614767303.

The spelling of 78656631 in words is "seventy-eight million, six hundred fifty-six thousand, six hundred thirty-one".