77915880 has 192 divisors, whose sum is σ = 295776000. Its totient is φ = 17781120.

The previous prime is 77915861. The next prime is 77915891. The reversal of 77915880 is 8851977.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 123165 + ... + 123795.

It is an arithmetic number, because the mean of its divisors is an integer number (1540500).

Almost surely, 2^77915880 is an apocalyptic number.

77915880 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77915880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (147888000).

77915880 is an abundant number, since it is smaller than the sum of its proper divisors (217860120).

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

77915880 is a wasteful number, since it uses less digits than its factorization.

77915880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 669 (or 648 counting only the distinct ones).

The product of its (nonzero) digits is 141120, while the sum is 45.

The square root of 77915880 is about 8826.9972244246. The cubic root of 77915880 is about 427.1122163188.

The spelling of 77915880 in words is "seventy-seven million, nine hundred fifteen thousand, eight hundred eighty".