166564819 has 2 divisors, whose sum is σ = 166564820. Its totient is φ = 166564818.

The previous prime is 166564813. The next prime is 166564883. The reversal of 166564819 is 918465661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 166564819 - 2¹¹ = 166562771 is a prime.

It is a super-2 number, since 2×166564819² = 55487677857005522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (166564813) 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, 83282409 + 83282410.

It is an arithmetic number, because the mean of its divisors is an integer number (83282410).

Almost surely, 2^166564819 is an apocalyptic number.

166564819 is a deficient number, since it is larger than the sum of its proper divisors (1).

166564819 is an equidigital number, since it uses as much as digits as its factorization.

166564819 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 311040, while the sum is 46.

The square root of 166564819 is about 12905.9993413916. Note that the first 3 decimals coincide. The cubic root of 166564819 is about 550.2090874456.

The spelling of 166564819 in words is "one hundred sixty-six million, five hundred sixty-four thousand, eight hundred nineteen".