81651156 has 48 divisors (see below), whose sum is σ = 196984704. Its totient is φ = 26303616.

The previous prime is 81651133. The next prime is 81651169. The reversal of 81651156 is 65115618.

It is a super-2 number, since 2×81651156² = 13333822552272672, 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 in 15 ways as a sum of consecutive naturals, for example, 76281 + ... + 77343.

It is an arithmetic number, because the mean of its divisors is an integer number (4103848).

Almost surely, 2^81651156 is an apocalyptic number.

It is an amenable number.

81651156 is an abundant number, since it is smaller than the sum of its proper divisors (115333548).

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

81651156 is a wasteful number, since it uses less digits than its factorization.

81651156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1280 (or 1278 counting only the distinct ones).

The product of its digits is 7200, while the sum is 33.

The square root of 81651156 is about 9036.1029210606. The cubic root of 81651156 is about 433.8311971393.

The spelling of 81651156 in words is "eighty-one million, six hundred fifty-one thousand, one hundred fifty-six".