81975552 has 36 divisors (see below), whose sum is σ = 218176560. Its totient is φ = 27324928.

The previous prime is 81975541. The next prime is 81975559. The reversal of 81975552 is 25557918.

It is a super-2 number, since 2×81975552² = 13439982251409408, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81975559) 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, 52602 + ... + 54137.

It is an arithmetic number, because the mean of its divisors is an integer number (6060460).

Almost surely, 2^81975552 is an apocalyptic number.

It is an amenable number.

81975552 is an abundant number, since it is smaller than the sum of its proper divisors (136201008).

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

81975552 is a wasteful number, since it uses less digits than its factorization.

81975552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106758 (or 106744 counting only the distinct ones).

The product of its digits is 126000, while the sum is 42.

The square root of 81975552 is about 9054.0351225296. The cubic root of 81975552 is about 434.4049679098.

The spelling of 81975552 in words is "eighty-one million, nine hundred seventy-five thousand, five hundred fifty-two".