166557187 has 2 divisors, whose sum is σ = 166557188. Its totient is φ = 166557186.

The previous prime is 166557169. The next prime is 166557197. The reversal of 166557187 is 781755661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 166557187 - 2¹¹ = 166555139 is a prime.

It is not a weakly prime, because it can be changed into another prime (166557107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83278593 + 83278594.

It is an arithmetic number, because the mean of its divisors is an integer number (83278594).

Almost surely, 2^166557187 is an apocalyptic number.

166557187 is a deficient number, since it is larger than the sum of its proper divisors (1).

166557187 is an equidigital number, since it uses as much as digits as its factorization.

166557187 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 352800, while the sum is 46.

The square root of 166557187 is about 12905.7036615599. The cubic root of 166557187 is about 550.2006837905.

The spelling of 166557187 in words is "one hundred sixty-six million, five hundred fifty-seven thousand, one hundred eighty-seven".