81625536 has 56 divisors (see below), whose sum is σ = 239969040. Its totient is φ = 27207936.

The previous prime is 81625519. The next prime is 81625541. The reversal of 81625536 is 63552618.

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 81625536.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21891 + ... + 25346.

Almost surely, 2^81625536 is an apocalyptic number.

It is an amenable number.

81625536 is an abundant number, since it is smaller than the sum of its proper divisors (158343504).

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

81625536 is a wasteful number, since it uses less digits than its factorization.

81625536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47258 (or 47242 counting only the distinct ones).

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

The square root of 81625536 is about 9034.6851633026. The cubic root of 81625536 is about 433.7858174267.

The spelling of 81625536 in words is "eighty-one million, six hundred twenty-five thousand, five hundred thirty-six".