78978564 has 120 divisors (see below), whose sum is σ = 239057280. Its totient is φ = 22270464.

The previous prime is 78978547. The next prime is 78978577. The reversal of 78978564 is 46587987.

78978564 is a `hidden beast` number, since 7 + 8 + 9 + 78 + 564 = 666.

It is a super-2 number, since 2×78978564² = 12475227143004192, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 78978564.

It is an unprimeable number.

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 39 ways as a sum of consecutive naturals, for example, 219817 + ... + 220175.

It is an arithmetic number, because the mean of its divisors is an integer number (1992144).

Almost surely, 2^78978564 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 78978564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119528640).

78978564 is an abundant number, since it is smaller than the sum of its proper divisors (160078716).

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

78978564 is a wasteful number, since it uses less digits than its factorization.

78978564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 479 (or 468 counting only the distinct ones).

The product of its digits is 3386880, while the sum is 54.

The square root of 78978564 is about 8886.9884662916. The cubic root of 78978564 is about 429.0452297170.

It can be divided in two parts, 7897 and 8564, that added together give a palindrome (16461).

The spelling of 78978564 in words is "seventy-eight million, nine hundred seventy-eight thousand, five hundred sixty-four".