87639031 has 4 divisors (see below), whose sum is σ = 89677192. Its totient is φ = 85600872.

The previous prime is 87639023. The next prime is 87639049. The reversal of 87639031 is 13093678.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 87639031 - 2³ = 87639023 is a prime.

It is a super-2 number, since 2×87639031² = 15361199509237922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87639011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1019016 + ... + 1019101.

It is an arithmetic number, because the mean of its divisors is an integer number (22419298).

Almost surely, 2^87639031 is an apocalyptic number.

87639031 is a deficient number, since it is larger than the sum of its proper divisors (2038161).

87639031 is a wasteful number, since it uses less digits than its factorization.

87639031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2038160.

The product of its (nonzero) digits is 27216, while the sum is 37.

The square root of 87639031 is about 9361.5720367895. The cubic root of 87639031 is about 444.1870120268.

The spelling of 87639031 in words is "eighty-seven million, six hundred thirty-nine thousand, thirty-one".