78717690 has 32 divisors (see below), whose sum is σ = 209914560. Its totient is φ = 20991312.

The previous prime is 78717689. The next prime is 78717713. The reversal of 78717690 is 9671787.

It is a happy number.

It is a super-2 number, since 2×78717690² = 12392949437872200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 145504 + ... + 146043.

It is an arithmetic number, because the mean of its divisors is an integer number (6559830).

Almost surely, 2^78717690 is an apocalyptic number.

78717690 is an abundant number, since it is smaller than the sum of its proper divisors (131196870).

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

78717690 is a wasteful number, since it uses less digits than its factorization.

78717690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 291563 (or 291557 counting only the distinct ones).

The product of its (nonzero) digits is 148176, while the sum is 45.

The square root of 78717690 is about 8872.2990256190. The cubic root of 78717690 is about 428.5723157124.

The spelling of 78717690 in words is "seventy-eight million, seven hundred seventeen thousand, six hundred ninety".