81873125 has 20 divisors (see below), whose sum is σ = 103401276. Its totient is φ = 64800000.

The previous prime is 81873097. The next prime is 81873137. The reversal of 81873125 is 52137818.

It can be written as a sum of positive squares in 10 ways, for example, as 13082689 + 68790436 = 3617^2 + 8294^2 .

It is not a de Polignac number, because 81873125 - 2²⁴ = 65095909 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 62477 + ... + 63773.

Almost surely, 2^81873125 is an apocalyptic number.

It is an amenable number.

81873125 is a deficient number, since it is larger than the sum of its proper divisors (21528151).

81873125 is a wasteful number, since it uses less digits than its factorization.

81873125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1418 (or 1403 counting only the distinct ones).

The product of its digits is 13440, while the sum is 35.

The square root of 81873125 is about 9048.3769262780. The cubic root of 81873125 is about 434.2239653985.

The spelling of 81873125 in words is "eighty-one million, eight hundred seventy-three thousand, one hundred twenty-five".