78661688 has 32 divisors (see below), whose sum is σ = 174376800. Its totient is φ = 32548992.

The previous prime is 78661621. The next prime is 78661697. The reversal of 78661688 is 88616687.

It is a super-2 number, since 2×78661688² = 12375322318018688, which contains 22 as substring.

It is a Smith number, since the sum of its digits (50) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22595 + ... + 25842.

It is an arithmetic number, because the mean of its divisors is an integer number (5449275).

Almost surely, 2^78661688 is an apocalyptic number.

It is an amenable number.

78661688 is an abundant number, since it is smaller than the sum of its proper divisors (95715112).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78661688 is a wasteful number, since it uses less digits than its factorization.

78661688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48479 (or 48475 counting only the distinct ones).

The product of its digits is 774144, while the sum is 50.

The square root of 78661688 is about 8869.1424613657. The cubic root of 78661688 is about 428.4706587629.

The spelling of 78661688 in words is "seventy-eight million, six hundred sixty-one thousand, six hundred eighty-eight".