87639812 has 12 divisors (see below), whose sum is σ = 165167436. Its totient is φ = 40449120.

The previous prime is 87639809. The next prime is 87639823. The reversal of 87639812 is 21893678.

It can be written as a sum of positive squares in 2 ways, for example, as 9388096 + 78251716 = 3064^2 + 8846^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 842639 + ... + 842742.

It is an arithmetic number, because the mean of its divisors is an integer number (13763953).

Almost surely, 2^87639812 is an apocalyptic number.

It is an amenable number.

87639812 is a deficient number, since it is larger than the sum of its proper divisors (77527624).

87639812 is a wasteful number, since it uses less digits than its factorization.

87639812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1685398 (or 1685396 counting only the distinct ones).

The product of its digits is 145152, while the sum is 44.

The square root of 87639812 is about 9361.6137497763. The cubic root of 87639812 is about 444.1883314885.

The spelling of 87639812 in words is "eighty-seven million, six hundred thirty-nine thousand, eight hundred twelve".