87638831 has 4 divisors (see below), whose sum is σ = 100158672. Its totient is φ = 75118992.

The previous prime is 87638827. The next prime is 87638843. The reversal of 87638831 is 13883678.

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 87638831 - 2² = 87638827 is a prime.

It is a super-2 number, since 2×87638831² = 15361129398093122, 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 (87638851) 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, 6259910 + ... + 6259923.

It is an arithmetic number, because the mean of its divisors is an integer number (25039668).

Almost surely, 2^87638831 is an apocalyptic number.

87638831 is a deficient number, since it is larger than the sum of its proper divisors (12519841).

87638831 is a wasteful number, since it uses less digits than its factorization.

87638831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12519840.

The product of its digits is 193536, while the sum is 44.

The square root of 87638831 is about 9361.5613548168. The cubic root of 87638831 is about 444.1866741353.

The spelling of 87638831 in words is "eighty-seven million, six hundred thirty-eight thousand, eight hundred thirty-one".