78117984 has 72 divisors (see below), whose sum is σ = 253890000. Its totient is φ = 22318848.

The previous prime is 78117983. The next prime is 78118031. The reversal of 78117984 is 48971187.

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×78117984² = 12204838848448512, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78117983) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17359 + ... + 21390.

It is an arithmetic number, because the mean of its divisors is an integer number (3526250).

Almost surely, 2^78117984 is an apocalyptic number.

It is an amenable number.

78117984 is an abundant number, since it is smaller than the sum of its proper divisors (175772016).

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

78117984 is a wasteful number, since it uses less digits than its factorization.

78117984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38772 (or 38761 counting only the distinct ones).

The product of its digits is 112896, while the sum is 45.

The square root of 78117984 is about 8838.4378710268. The cubic root of 78117984 is about 427.4811892821.

The spelling of 78117984 in words is "seventy-eight million, one hundred seventeen thousand, nine hundred eighty-four".