77648820 has 48 divisors (see below), whose sum is σ = 228863040. Its totient is φ = 19616256.

The previous prime is 77648807. The next prime is 77648849. The reversal of 77648820 is 2884677.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32917 + ... + 35196.

It is an arithmetic number, because the mean of its divisors is an integer number (4767980).

Almost surely, 2^77648820 is an apocalyptic number.

It is an amenable number.

77648820 is an abundant number, since it is smaller than the sum of its proper divisors (151214220).

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

77648820 is a wasteful number, since it uses less digits than its factorization.

77648820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68144 (or 68142 counting only the distinct ones).

The product of its (nonzero) digits is 150528, while the sum is 42.

The square root of 77648820 is about 8811.8567850369. The cubic root of 77648820 is about 426.6236759527.

The spelling of 77648820 in words is "seventy-seven million, six hundred forty-eight thousand, eight hundred twenty".