66557125 has 16 divisors (see below), whose sum is σ = 87952176. Its totient is φ = 50112000.

The previous prime is 66557107. The next prime is 66557129. The reversal of 66557125 is 52175566.

It can be written as a sum of positive squares in 8 ways, for example, as 11826721 + 54730404 = 3439^2 + 7398^2 .

It is not a de Polignac number, because 66557125 - 2⁹ = 66556613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66557129) 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, 13536 + ... + 17785.

It is an arithmetic number, because the mean of its divisors is an integer number (5497011).

Almost surely, 2^66557125 is an apocalyptic number.

It is an amenable number.

66557125 is a deficient number, since it is larger than the sum of its proper divisors (21395051).

66557125 is a wasteful number, since it uses less digits than its factorization.

66557125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31353 (or 31343 counting only the distinct ones).

The product of its digits is 63000, while the sum is 37.

The square root of 66557125 is about 8158.2550217556. The cubic root of 66557125 is about 405.2579264415.

The spelling of 66557125 in words is "sixty-six million, five hundred fifty-seven thousand, one hundred twenty-five".