81625856 has 36 divisors (see below), whose sum is σ = 175473312. Its totient is φ = 37671936.

The previous prime is 81625853. The next prime is 81625879. The reversal of 81625856 is 65852618.

It is not an unprimeable number, because it can be changed into a prime (81625853) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8936 + ... + 15591.

Almost surely, 2^81625856 is an apocalyptic number.

It is an amenable number.

81625856 is an abundant number, since it is smaller than the sum of its proper divisors (93847456).

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

81625856 is a wasteful number, since it uses less digits than its factorization.

81625856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24556 (or 24542 counting only the distinct ones).

The product of its digits is 115200, while the sum is 41.

The square root of 81625856 is about 9034.7028728121. The cubic root of 81625856 is about 433.7863842888.

The spelling of 81625856 in words is "eighty-one million, six hundred twenty-five thousand, eight hundred fifty-six".