78564420 has 72 divisors (see below), whose sum is σ = 259983360. Its totient is φ = 19045440.

The previous prime is 78564413. The next prime is 78564427. The reversal of 78564420 is 2446587.

78564420 is a `hidden beast` number, since 7 + 8 + 5 + 644 + 2 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (78564413) and next prime (78564427).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (78564427) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17860 + ... + 21819.

It is an arithmetic number, because the mean of its divisors is an integer number (3610880).

Almost surely, 2^78564420 is an apocalyptic number.

It is an amenable number.

78564420 is an abundant number, since it is smaller than the sum of its proper divisors (181418940).

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

78564420 is a wasteful number, since it uses less digits than its factorization.

78564420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39705 (or 39700 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 36.

The square root of 78564420 is about 8863.6572587166. The cubic root of 78564420 is about 428.2939794710.

The spelling of 78564420 in words is "seventy-eight million, five hundred sixty-four thousand, four hundred twenty".