166555057 has 2 divisors, whose sum is σ = 166555058. Its totient is φ = 166555056.

The previous prime is 166555043. The next prime is 166555087. The reversal of 166555057 is 750555661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 101123136 + 65431921 = 10056^2 + 8089^2 .

It is a cyclic number.

It is not a de Polignac number, because 166555057 - 2⁷ = 166554929 is a prime.

It is not a weakly prime, because it can be changed into another prime (166555027) 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, 83277528 + 83277529.

It is an arithmetic number, because the mean of its divisors is an integer number (83277529).

Almost surely, 2^166555057 is an apocalyptic number.

It is an amenable number.

166555057 is a deficient number, since it is larger than the sum of its proper divisors (1).

166555057 is an equidigital number, since it uses as much as digits as its factorization.

166555057 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 157500, while the sum is 40.

The square root of 166555057 is about 12905.6211396430. The cubic root of 166555057 is about 550.1983383849.

It can be divided in two parts, 16655 and 5057, that added together give a palindrome (21712).

The spelling of 166555057 in words is "one hundred sixty-six million, five hundred fifty-five thousand, fifty-seven".