87639720 has 128 divisors (see below), whose sum is σ = 303747840. Its totient is φ = 19814400.

The previous prime is 87639703. The next prime is 87639733. The reversal of 87639720 is 2793678.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 84324 + ... + 85356.

It is an arithmetic number, because the mean of its divisors is an integer number (2373030).

Almost surely, 2^87639720 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 87639720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (151873920).

87639720 is an abundant number, since it is smaller than the sum of its proper divisors (216108120).

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

87639720 is a wasteful number, since it uses less digits than its factorization.

87639720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1155 (or 1151 counting only the distinct ones).

The product of its (nonzero) digits is 127008, while the sum is 42.

The square root of 87639720 is about 9361.6088360922. The cubic root of 87639720 is about 444.1881760594.

The spelling of 87639720 in words is "eighty-seven million, six hundred thirty-nine thousand, seven hundred twenty".