81953572 has 12 divisors (see below), whose sum is σ = 143577756. Its totient is φ = 40931360.

The previous prime is 81953567. The next prime is 81953587. The reversal of 81953572 is 27535918.

It can be written as a sum of positive squares in 2 ways, for example, as 29333056 + 52620516 = 5416^2 + 7254^2 .

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, 7123 + ... + 14650.

It is an arithmetic number, because the mean of its divisors is an integer number (11964813).

Almost surely, 2^81953572 is an apocalyptic number.

It is an amenable number.

81953572 is a deficient number, since it is larger than the sum of its proper divisors (61624184).

81953572 is a wasteful number, since it uses less digits than its factorization.

81953572 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22718 (or 22716 counting only the distinct ones).

The product of its digits is 75600, while the sum is 40.

The square root of 81953572 is about 9052.8212177199. The cubic root of 81953572 is about 434.3661389563.

The spelling of 81953572 in words is "eighty-one million, nine hundred fifty-three thousand, five hundred seventy-two".