81988256 has 24 divisors (see below), whose sum is σ = 184474080. Its totient is φ = 35137728.

The previous prime is 81988243. The next prime is 81988303. The reversal of 81988256 is 65288918.

It is a self number, because there is not a number n which added to its sum of digits gives 81988256.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 182786 + ... + 183233.

It is an arithmetic number, because the mean of its divisors is an integer number (7686420).

Almost surely, 2^81988256 is an apocalyptic number.

It is an amenable number.

81988256 is an abundant number, since it is smaller than the sum of its proper divisors (102485824).

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

81988256 is a wasteful number, since it uses less digits than its factorization.

81988256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 366036 (or 366028 counting only the distinct ones).

The product of its digits is 276480, while the sum is 47.

The square root of 81988256 is about 9054.7366609968. The cubic root of 81988256 is about 434.4274071027.

The spelling of 81988256 in words is "eighty-one million, nine hundred eighty-eight thousand, two hundred fifty-six".