166665923 has 2 divisors, whose sum is σ = 166665924. Its totient is φ = 166665922.

The previous prime is 166665913. The next prime is 166665937. The reversal of 166665923 is 329566661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 166665923 - 2⁴ = 166665907 is a prime.

It is not a weakly prime, because it can be changed into another prime (166665913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83332961 + 83332962.

It is an arithmetic number, because the mean of its divisors is an integer number (83332962).

Almost surely, 2^166665923 is an apocalyptic number.

166665923 is a deficient number, since it is larger than the sum of its proper divisors (1).

166665923 is an equidigital number, since it uses as much as digits as its factorization.

166665923 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 349920, while the sum is 44.

The square root of 166665923 is about 12909.9156852398. The cubic root of 166665923 is about 550.3203896368.

The spelling of 166665923 in words is "one hundred sixty-six million, six hundred sixty-five thousand, nine hundred twenty-three".