87815790 has 24 divisors (see below), whose sum is σ = 228321288. Its totient is φ = 23417520.

The previous prime is 87815779. The next prime is 87815807. The reversal of 87815790 is 9751878.

87815790 is a `hidden beast` number, since 8 + 78 + 1 + 579 + 0 = 666.

It is a super-2 number, since 2×87815790² = 15423225946648200, which contains 22 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

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

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 487776 + ... + 487955.

It is an arithmetic number, because the mean of its divisors is an integer number (9513387).

Almost surely, 2^87815790 is an apocalyptic number.

87815790 is an abundant number, since it is smaller than the sum of its proper divisors (140505498).

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

87815790 is a wasteful number, since it uses less digits than its factorization.

87815790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 975744 (or 975741 counting only the distinct ones).

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

The square root of 87815790 is about 9371.0079500553. The cubic root of 87815790 is about 444.4854381401.

The spelling of 87815790 in words is "eighty-seven million, eight hundred fifteen thousand, seven hundred ninety".