81886656 has 56 divisors (see below), whose sum is σ = 228071680. Its totient is φ = 25857792.

The previous prime is 81886639. The next prime is 81886667. The reversal of 81886656 is 65668818.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (48).

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 7 ways as a sum of consecutive naturals, for example, 7576 + ... + 14871.

Almost surely, 2^81886656 is an apocalyptic number.

It is an amenable number.

81886656 is an abundant number, since it is smaller than the sum of its proper divisors (146185024).

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

81886656 is a wasteful number, since it uses less digits than its factorization.

81886656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22481 (or 22471 counting only the distinct ones).

The product of its digits is 552960, while the sum is 48.

The square root of 81886656 is about 9049.1245985454. The cubic root of 81886656 is about 434.2478851761.

The spelling of 81886656 in words is "eighty-one million, eight hundred eighty-six thousand, six hundred fifty-six".