81587152 has 10 divisors (see below), whose sum is σ = 158075138. Its totient is φ = 40793568.

The previous prime is 81587119. The next prime is 81587167. The reversal of 81587152 is 25178518.

It can be written as a sum of positive squares in only one way, i.e., 60279696 + 21307456 = 7764^2 + 4616^2 .

It is a super-2 number, since 2×81587152² = 13312926742942208, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2549583 + ... + 2549614.

Almost surely, 2^81587152 is an apocalyptic number.

It is an amenable number.

81587152 is a deficient number, since it is larger than the sum of its proper divisors (76487986).

81587152 is a wasteful number, since it uses less digits than its factorization.

81587152 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5099205 (or 5099199 counting only the distinct ones).

The product of its digits is 22400, while the sum is 37.

The square root of 81587152 is about 9032.5606557609. The cubic root of 81587152 is about 433.7178115622.

The spelling of 81587152 in words is "eighty-one million, five hundred eighty-seven thousand, one hundred fifty-two".