77915904 has 144 divisors (see below), whose sum is σ = 236646144. Its totient is φ = 22528000.

The previous prime is 77915891. The next prime is 77915909. The reversal of 77915904 is 40951977.

It is a happy number.

It is a super-2 number, since 2×77915904² = 12141776192274432, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77915909) 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, 194104 + ... + 194504.

It is an arithmetic number, because the mean of its divisors is an integer number (1643376).

Almost surely, 2^77915904 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 77915904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118323072).

77915904 is an abundant number, since it is smaller than the sum of its proper divisors (158730240).

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

77915904 is a wasteful number, since it uses less digits than its factorization.

77915904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 454 (or 440 counting only the distinct ones).

The product of its (nonzero) digits is 79380, while the sum is 42.

The square root of 77915904 is about 8826.9985838902. The cubic root of 77915904 is about 427.1122601725.

It can be divided in two parts, 7791 and 5904, that added together give a triangular number (13695 = T₁₆₅).

The spelling of 77915904 in words is "seventy-seven million, nine hundred fifteen thousand, nine hundred four".