78647631 has 16 divisors (see below), whose sum is σ = 110697600. Its totient is φ = 49530528.

The previous prime is 78647617. The next prime is 78647633. The reversal of 78647631 is 13674687.

It is not a de Polignac number, because 78647631 - 2⁵ = 78647599 is a prime.

It is a super-2 number, since 2×78647631² = 12370899723824322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78647633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20400 + ... + 23946.

It is an arithmetic number, because the mean of its divisors is an integer number (6918600).

Almost surely, 2^78647631 is an apocalyptic number.

78647631 is a deficient number, since it is larger than the sum of its proper divisors (32049969).

78647631 is a wasteful number, since it uses less digits than its factorization.

78647631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3958.

The product of its digits is 169344, while the sum is 42.

The square root of 78647631 is about 8868.3499592653. The cubic root of 78647631 is about 428.4451343896.

The spelling of 78647631 in words is "seventy-eight million, six hundred forty-seven thousand, six hundred thirty-one".