81471426625 has 8 divisors (see below), whose sum is σ = 101676340584. Its totient is φ = 65177141200.

The previous prime is 81471426611. The next prime is 81471426667. The reversal of 81471426625 is 52662417418.

It is a Cunningham number, because it is equal to 285432²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 1 + 81471426624 = 1^2 + 285432^2 .

It is not a de Polignac number, because 81471426625 - 2⁷ = 81471426497 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 325885582 + ... + 325885831.

It is an arithmetic number, because the mean of its divisors is an integer number (12709542573).

Almost surely, 2^81471426625 is an apocalyptic number.

It is an amenable number.

81471426625 is a deficient number, since it is larger than the sum of its proper divisors (20204913959).

81471426625 is an equidigital number, since it uses as much as digits as its factorization.

81471426625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 651771428 (or 651771418 counting only the distinct ones).

The product of its digits is 645120, while the sum is 46.

The spelling of 81471426625 in words is "eighty-one billion, four hundred seventy-one million, four hundred twenty-six thousand, six hundred twenty-five".