81974825 has 12 divisors (see below), whose sum is σ = 103082688. Its totient is φ = 64654800.

The previous prime is 81974821. The next prime is 81974861. The reversal of 81974825 is 52847918.

It is not a de Polignac number, because 81974825 - 2² = 81974821 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81974821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21317 + ... + 24866.

It is an arithmetic number, because the mean of its divisors is an integer number (8590224).

Almost surely, 2^81974825 is an apocalyptic number.

It is an amenable number.

81974825 is a deficient number, since it is larger than the sum of its proper divisors (21107863).

81974825 is a wasteful number, since it uses less digits than its factorization.

81974825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46264 (or 46259 counting only the distinct ones).

The product of its digits is 161280, while the sum is 44.

The square root of 81974825 is about 9053.9949745955. The cubic root of 81974825 is about 434.4036837329.

The spelling of 81974825 in words is "eighty-one million, nine hundred seventy-four thousand, eight hundred twenty-five".