78939690 has 16 divisors (see below), whose sum is σ = 189455328. Its totient is φ = 21050576.

The previous prime is 78939689. The next prime is 78939697. The reversal of 78939690 is 9693987.

It is a super-2 number, since 2×78939690² = 12462949314592200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78939697) 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 7 ways as a sum of consecutive naturals, for example, 1315632 + ... + 1315691.

It is an arithmetic number, because the mean of its divisors is an integer number (11840958).

Almost surely, 2^78939690 is an apocalyptic number.

78939690 is an abundant number, since it is smaller than the sum of its proper divisors (110515638).

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

78939690 is a wasteful number, since it uses less digits than its factorization.

78939690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2631333.

The product of its (nonzero) digits is 734832, while the sum is 51.

The square root of 78939690 is about 8884.8010669908. The cubic root of 78939690 is about 428.9748247842.

The spelling of 78939690 in words is "seventy-eight million, nine hundred thirty-nine thousand, six hundred ninety".