81655236 has 96 divisors (see below), whose sum is σ = 240060800. Its totient is φ = 23794560.

The previous prime is 81655201. The next prime is 81655247. The reversal of 81655236 is 63255618.

It is a super-3 number, since 3×81655236³ (a number of 25 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 81655236.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 25146 + ... + 28206.

Almost surely, 2^81655236 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81655236, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120030400).

81655236 is an abundant number, since it is smaller than the sum of its proper divisors (158405564).

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

81655236 is a wasteful number, since it uses less digits than its factorization.

81655236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3106 (or 3098 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The square root of 81655236 is about 9036.3286792812. The cubic root of 81655236 is about 433.8384230088.

The spelling of 81655236 in words is "eighty-one million, six hundred fifty-five thousand, two hundred thirty-six".