81957008 has 30 divisors (see below), whose sum is σ = 184718646. Its totient is φ = 35124096.

The previous prime is 81956999. The next prime is 81957061. The reversal of 81957008 is 80075918.

It can be written as a sum of positive squares in only one way, i.e., 43665664 + 38291344 = 6608^2 + 6188^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 51485 + ... + 53052.

Almost surely, 2^81957008 is an apocalyptic number.

It is an amenable number.

81957008 is an abundant number, since it is smaller than the sum of its proper divisors (102761638).

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

81957008 is a wasteful number, since it uses less digits than its factorization.

81957008 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104559 (or 104546 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 38.

The square root of 81957008 is about 9053.0109908251. The cubic root of 81957008 is about 434.3722093087.

The spelling of 81957008 in words is "eighty-one million, nine hundred fifty-seven thousand, eight".