81975890325 has 48 divisors (see below), whose sum is σ = 154933278080. Its totient is φ = 37465528320.

The previous prime is 81975890309. The next prime is 81975890327. The reversal of 81975890325 is 52309857918.

It is not a de Polignac number, because 81975890325 - 2⁴ = 81975890309 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81975890327) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2428161 + ... + 2461689.

Almost surely, 2^81975890325 is an apocalyptic number.

It is an amenable number.

81975890325 is a deficient number, since it is larger than the sum of its proper divisors (72957387755).

81975890325 is a wasteful number, since it uses less digits than its factorization.

81975890325 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38206 (or 38201 counting only the distinct ones).

The product of its (nonzero) digits is 5443200, while the sum is 57.

The spelling of 81975890325 in words is "eighty-one billion, nine hundred seventy-five million, eight hundred ninety thousand, three hundred twenty-five".