81630656 has 28 divisors (see below), whose sum is σ = 164412168. Its totient is φ = 40204032.

The previous prime is 81630643. The next prime is 81630667. The reversal of 81630656 is 65603618.

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5231 + ... + 13806.

Almost surely, 2^81630656 is an apocalyptic number.

It is an amenable number.

81630656 is an abundant number, since it is smaller than the sum of its proper divisors (82781512).

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

81630656 is a wasteful number, since it uses less digits than its factorization.

81630656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19116 (or 19106 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 81630656 is about 9034.9685112899. The cubic root of 81630656 is about 433.7948870433.

The spelling of 81630656 in words is "eighty-one million, six hundred thirty thousand, six hundred fifty-six".