81587976 has 32 divisors (see below), whose sum is σ = 214706400. Its totient is φ = 25764480.

The previous prime is 81587963. The next prime is 81587983. The reversal of 81587976 is 67978518.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 89005 + ... + 89916.

It is an arithmetic number, because the mean of its divisors is an integer number (6709575).

Almost surely, 2^81587976 is an apocalyptic number.

It is an amenable number.

81587976 is an abundant number, since it is smaller than the sum of its proper divisors (133118424).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81587976 is a wasteful number, since it uses less digits than its factorization.

81587976 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178949 (or 178945 counting only the distinct ones).

The product of its digits is 846720, while the sum is 51.

The square root of 81587976 is about 9032.6062684034. The cubic root of 81587976 is about 433.7192716870.

The spelling of 81587976 in words is "eighty-one million, five hundred eighty-seven thousand, nine hundred seventy-six".