81330125 has 16 divisors (see below), whose sum is σ = 107473392. Its totient is φ = 61235200.

The previous prime is 81330113. The next prime is 81330173. The reversal of 81330125 is 52103318.

It can be written as a sum of positive squares in 8 ways, for example, as 4206601 + 77123524 = 2051^2 + 8782^2 .

It is not a de Polignac number, because 81330125 - 2⁸ = 81329869 is a prime.

It is a super-2 number, since 2×81330125² = 13229178465031250, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81330125.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17012 + ... + 21261.

It is an arithmetic number, because the mean of its divisors is an integer number (6717087).

Almost surely, 2^81330125 is an apocalyptic number.

81330125 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

81330125 is a deficient number, since it is larger than the sum of its proper divisors (26143267).

81330125 is a wasteful number, since it uses less digits than its factorization.

81330125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38305 (or 38295 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 81330125 is about 9018.3216287733. The cubic root of 81330125 is about 433.2618800660.

The spelling of 81330125 in words is "eighty-one million, three hundred thirty thousand, one hundred twenty-five".