87691988 has 12 divisors (see below), whose sum is σ = 153570900. Its totient is φ = 43814592.

The previous prime is 87691979. The next prime is 87691991. The reversal of 87691988 is 88919678.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 31561924 + 56130064 = 5618^2 + 7492^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 881 + ... + 13272.

It is an arithmetic number, because the mean of its divisors is an integer number (12797575).

Almost surely, 2^87691988 is an apocalyptic number.

It is an amenable number.

87691988 is a deficient number, since it is larger than the sum of its proper divisors (65878912).

87691988 is a wasteful number, since it uses less digits than its factorization.

87691988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15706 (or 15704 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 56.

The square root of 87691988 is about 9364.4000341720. The cubic root of 87691988 is about 444.2764625640.

The spelling of 87691988 in words is "eighty-seven million, six hundred ninety-one thousand, nine hundred eighty-eight".