666643166 has 32 divisors (see below), whose sum is σ = 1168446720. Its totient is φ = 279360576.

The previous prime is 666643157. The next prime is 666643181. The reversal of 666643166 is 661346666.

It is a super-2 number, since 2×666643166² = 888826221549007112, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 127826 + ... + 132938.

It is an arithmetic number, because the mean of its divisors is an integer number (36513960).

Almost surely, 2^666643166 is an apocalyptic number.

666643166 is a deficient number, since it is larger than the sum of its proper divisors (501803554).

666643166 is a wasteful number, since it uses less digits than its factorization.

666643166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5328.

The product of its digits is 559872, while the sum is 44.

The square root of 666643166 is about 25819.4338822523. The cubic root of 666643166 is about 873.5701997540.

The spelling of 666643166 in words is "six hundred sixty-six million, six hundred forty-three thousand, one hundred sixty-six".