72166257 has 24 divisors (see below), whose sum is σ = 106176096. Its totient is φ = 47226816.

The previous prime is 72166247. The next prime is 72166271. The reversal of 72166257 is 75266127.

72166257 is a `hidden beast` number, since 7 + 21 + 6 + 625 + 7 = 666.

It is not a de Polignac number, because 72166257 - 2²⁴ = 55389041 is a prime.

It is not an unprimeable number, because it can be changed into a prime (72166247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 131658 + ... + 132204.

It is an arithmetic number, because the mean of its divisors is an integer number (4424004).

Almost surely, 2^72166257 is an apocalyptic number.

It is an amenable number.

72166257 is a deficient number, since it is larger than the sum of its proper divisors (34009839).

72166257 is a wasteful number, since it uses less digits than its factorization.

72166257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 797 (or 794 counting only the distinct ones).

The product of its digits is 35280, while the sum is 36.

The square root of 72166257 is about 8495.0725129336. The cubic root of 72166257 is about 416.3367300271.

The spelling of 72166257 in words is "seventy-two million, one hundred sixty-six thousand, two hundred fifty-seven".