78642920 has 64 divisors (see below), whose sum is σ = 183859200. Its totient is φ = 30251520.

The previous prime is 78642853. The next prime is 78642923. The reversal of 78642920 is 2924687.

It is a super-2 number, since 2×78642920² = 12369417732252800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78642923) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 129257 + ... + 129863.

It is an arithmetic number, because the mean of its divisors is an integer number (2872800).

Almost surely, 2^78642920 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78642920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91929600).

78642920 is an abundant number, since it is smaller than the sum of its proper divisors (105216280).

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

78642920 is a wasteful number, since it uses less digits than its factorization.

78642920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 738 (or 734 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 38.

The square root of 78642920 is about 8868.0843478172. The cubic root of 78642920 is about 428.4365795851.

The spelling of 78642920 in words is "seventy-eight million, six hundred forty-two thousand, nine hundred twenty".