66166731 has 12 divisors (see below), whose sum is σ = 95701008. Its totient is φ = 44052624.

The previous prime is 66166729. The next prime is 66166733. The reversal of 66166731 is 13766166.

66166731 is a `hidden beast` number, since 6 + 616 + 6 + 7 + 31 = 666.

It is an interprime number because it is at equal distance from previous prime (66166729) and next prime (66166733).

It is not a de Polignac number, because 66166731 - 2¹ = 66166729 is a prime.

It is a super-2 number, since 2×66166731² = 8756072582452722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66166733) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2941 + ... + 11873.

It is an arithmetic number, because the mean of its divisors is an integer number (7975084).

Almost surely, 2^66166731 is an apocalyptic number.

66166731 is a deficient number, since it is larger than the sum of its proper divisors (29534277).

66166731 is a wasteful number, since it uses less digits than its factorization.

66166731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9762 (or 9759 counting only the distinct ones).

The product of its digits is 27216, while the sum is 36.

The square root of 66166731 is about 8134.2935157271. The cubic root of 66166731 is about 404.4640189280.

The spelling of 66166731 in words is "sixty-six million, one hundred sixty-six thousand, seven hundred thirty-one".