81131152 has 10 divisors (see below), whose sum is σ = 157191638. Its totient is φ = 40565568.

The previous prime is 81131147. The next prime is 81131173. The reversal of 81131152 is 25113118.

It can be written as a sum of positive squares in only one way, i.e., 55890576 + 25240576 = 7476^2 + 5024^2 .

It is a super-3 number, since 3×81131152³ (a number of 25 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2535333 + ... + 2535364.

Almost surely, 2^81131152 is an apocalyptic number.

It is an amenable number.

81131152 is a deficient number, since it is larger than the sum of its proper divisors (76060486).

81131152 is a wasteful number, since it uses less digits than its factorization.

81131152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5070705 (or 5070699 counting only the distinct ones).

The product of its digits is 240, while the sum is 22.

The square root of 81131152 is about 9007.2832752168. The cubic root of 81131152 is about 432.9082685209.

The spelling of 81131152 in words is "eighty-one million, one hundred thirty-one thousand, one hundred fifty-two".