81925797 has 16 divisors (see below), whose sum is σ = 110328192. Its totient is φ = 54073920.

The previous prime is 81925787. The next prime is 81925819. The reversal of 81925797 is 79752918.

It is not a de Polignac number, because 81925797 - 2¹¹ = 81923749 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81925717) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 258283 + ... + 258599.

It is an arithmetic number, because the mean of its divisors is an integer number (6895512).

Almost surely, 2^81925797 is an apocalyptic number.

It is an amenable number.

81925797 is a deficient number, since it is larger than the sum of its proper divisors (28402395).

81925797 is a wasteful number, since it uses less digits than its factorization.

81925797 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 908.

The product of its digits is 317520, while the sum is 48.

The square root of 81925797 is about 9051.2870355547. The cubic root of 81925797 is about 434.3170628660.

The spelling of 81925797 in words is "eighty-one million, nine hundred twenty-five thousand, seven hundred ninety-seven".