78787631 has 12 divisors (see below), whose sum is σ = 86131512. Its totient is φ = 72030816.

The previous prime is 78787613. The next prime is 78787633. The reversal of 78787631 is 13678787.

It is not a de Polignac number, because 78787631 - 2¹⁰ = 78786607 is a prime.

It is a super-2 number, since 2×78787631² = 12414981597184322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78787633) 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 11 ways as a sum of consecutive naturals, for example, 15905 + ... + 20261.

It is an arithmetic number, because the mean of its divisors is an integer number (7177626).

Almost surely, 2^78787631 is an apocalyptic number.

78787631 is a deficient number, since it is larger than the sum of its proper divisors (7343881).

78787631 is a wasteful number, since it uses less digits than its factorization.

78787631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4490 (or 4477 counting only the distinct ones).

The product of its digits is 395136, while the sum is 47.

The square root of 78787631 is about 8876.2396880661. The cubic root of 78787631 is about 428.6992075760.

The spelling of 78787631 in words is "seventy-eight million, seven hundred eighty-seven thousand, six hundred thirty-one".