166591811 has 2 divisors, whose sum is σ = 166591812. Its totient is φ = 166591810.

The previous prime is 166591801. The next prime is 166591813. The reversal of 166591811 is 118195661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 166591811 - 2²² = 162397507 is a prime.

It is a Sophie Germain prime.

Together with 166591813, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (166591813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83295905 + 83295906.

It is an arithmetic number, because the mean of its divisors is an integer number (83295906).

Almost surely, 2^166591811 is an apocalyptic number.

166591811 is a deficient number, since it is larger than the sum of its proper divisors (1).

166591811 is an equidigital number, since it uses as much as digits as its factorization.

166591811 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12960, while the sum is 38.

The square root of 166591811 is about 12907.0450142548. The cubic root of 166591811 is about 550.2388064896.

The spelling of 166591811 in words is "one hundred sixty-six million, five hundred ninety-one thousand, eight hundred eleven".