87631809 has 4 divisors (see below), whose sum is σ = 116842416. Its totient is φ = 58421204.

The previous prime is 87631763. The next prime is 87631811. The reversal of 87631809 is 90813678.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 87631809 - 2⁷ = 87631681 is a prime.

It is a super-2 number, since 2×87631809² = 15358667897224962, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (87631849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14605299 + ... + 14605304.

It is an arithmetic number, because the mean of its divisors is an integer number (29210604).

Almost surely, 2^87631809 is an apocalyptic number.

It is an amenable number.

87631809 is a deficient number, since it is larger than the sum of its proper divisors (29210607).

87631809 is a wasteful number, since it uses less digits than its factorization.

87631809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29210606.

The product of its (nonzero) digits is 72576, while the sum is 42.

The square root of 87631809 is about 9361.1863030281. The cubic root of 87631809 is about 444.1748104363.

The spelling of 87631809 in words is "eighty-seven million, six hundred thirty-one thousand, eight hundred nine".