66172566 has 16 divisors (see below), whose sum is σ = 132447744. Its totient is φ = 22040424.

The previous prime is 66172549. The next prime is 66172591. The reversal of 66172566 is 66527166.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6015 + ... + 12981.

It is an arithmetic number, because the mean of its divisors is an integer number (8277984).

Almost surely, 2^66172566 is an apocalyptic number.

66172566 is an abundant number, since it is smaller than the sum of its proper divisors (66275178).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66172566 is a wasteful number, since it uses less digits than its factorization.

66172566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8555.

The product of its digits is 90720, while the sum is 39.

The square root of 66172566 is about 8134.6521744940. The cubic root of 66172566 is about 404.4759079753.

The spelling of 66172566 in words is "sixty-six million, one hundred seventy-two thousand, five hundred sixty-six".