81975888 has 100 divisors (see below), whose sum is σ = 242944768. Its totient is φ = 26671680.

The previous prime is 81975871. The next prime is 81975893. The reversal of 81975888 is 88857918.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 54993 + ... + 56463.

Almost surely, 2^81975888 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81975888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121472384).

81975888 is an abundant number, since it is smaller than the sum of its proper divisors (160968880).

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

81975888 is a wasteful number, since it uses less digits than its factorization.

81975888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1534 (or 1519 counting only the distinct ones).

The product of its digits is 1290240, while the sum is 54.

The square root of 81975888 is about 9054.0536777733. The cubic root of 81975888 is about 434.4055614196.

The spelling of 81975888 in words is "eighty-one million, nine hundred seventy-five thousand, eight hundred eighty-eight".