166692991 has 2 divisors, whose sum is σ = 166692992. Its totient is φ = 166692990.

The previous prime is 166692959. The next prime is 166692997. The reversal of 166692991 is 199296661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 166692991 - 2⁵ = 166692959 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166692997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83346495 + 83346496.

It is an arithmetic number, because the mean of its divisors is an integer number (83346496).

Almost surely, 2^166692991 is an apocalyptic number.

166692991 is a deficient number, since it is larger than the sum of its proper divisors (1).

166692991 is an equidigital number, since it uses as much as digits as its factorization.

166692991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 314928, while the sum is 49.

The square root of 166692991 is about 12910.9639841493. The cubic root of 166692991 is about 550.3501803017.

The spelling of 166692991 in words is "one hundred sixty-six million, six hundred ninety-two thousand, nine hundred ninety-one".