87218820 has 72 divisors (see below), whose sum is σ = 284922456. Its totient is φ = 21468672.

The previous prime is 87218777. The next prime is 87218821. The reversal of 87218820 is 2881278.

It can be written as a sum of positive squares in 4 ways, for example, as 6110784 + 81108036 = 2472^2 + 9006^2 .

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (87218821) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16297 + ... + 20976.

Almost surely, 2^87218820 is an apocalyptic number.

It is an amenable number.

87218820 is an abundant number, since it is smaller than the sum of its proper divisors (197703636).

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

87218820 is a wasteful number, since it uses less digits than its factorization.

87218820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37301 (or 37296 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 36.

The square root of 87218820 is about 9339.1016698610. The cubic root of 87218820 is about 443.4759461040.

The spelling of 87218820 in words is "eighty-seven million, two hundred eighteen thousand, eight hundred twenty".