666243137672166 has 16 divisors (see below), whose sum is σ = 1332748214913024. Its totient is φ = 222037389295944.

The previous prime is 666243137672153. The next prime is 666243137672237. The reversal of 666243137672166 is 661276731342666.

It is a super-2 number, since 2×666243137672166² (a number of 30 digits) contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 666243137672097 and 666243137672106.

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, 10914115630 + ... + 10914176673.

It is an arithmetic number, because the mean of its divisors is an integer number (83296763432064).

Almost surely, 2^{666243137672166} is an apocalyptic number.

666243137672166 is an abundant number, since it is smaller than the sum of its proper divisors (666505077240858).

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

666243137672166 is a wasteful number, since it uses less digits than its factorization.

666243137672166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21828297395.

The product of its digits is 329204736, while the sum is 66.

The spelling of 666243137672166 in words is "six hundred sixty-six trillion, two hundred forty-three billion, one hundred thirty-seven million, six hundred seventy-two thousand, one hundred sixty-six".