77438720 has 72 divisors (see below), whose sum is σ = 187639200. Its totient is φ = 30617600.

The previous prime is 77438719. The next prime is 77438747. The reversal of 77438720 is 2783477.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 128981 + ... + 129579.

It is an arithmetic number, because the mean of its divisors is an integer number (2606100).

Almost surely, 2^77438720 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 77438720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93819600).

77438720 is an abundant number, since it is smaller than the sum of its proper divisors (110200480).

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

77438720 is a wasteful number, since it uses less digits than its factorization.

77438720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 721 (or 707 counting only the distinct ones).

The product of its (nonzero) digits is 65856, while the sum is 38.

The square root of 77438720 is about 8799.9272724267. The cubic root of 77438720 is about 426.2385462590.

The spelling of 77438720 in words is "seventy-seven million, four hundred thirty-eight thousand, seven hundred twenty".