166891477 has 2 divisors, whose sum is σ = 166891478. Its totient is φ = 166891476.

The previous prime is 166891469. The next prime is 166891489. The reversal of 166891477 is 774198661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 164198596 + 2692881 = 12814^2 + 1641^2 .

It is a cyclic number.

It is not a de Polignac number, because 166891477 - 2³ = 166891469 is a prime.

It is a super-3 number, since 3×166891477³ (a number of 26 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 166891477.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166891447) 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, 83445738 + 83445739.

It is an arithmetic number, because the mean of its divisors is an integer number (83445739).

Almost surely, 2^166891477 is an apocalyptic number.

It is an amenable number.

166891477 is a deficient number, since it is larger than the sum of its proper divisors (1).

166891477 is an equidigital number, since it uses as much as digits as its factorization.

166891477 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 508032, while the sum is 49.

The square root of 166891477 is about 12918.6484200167. The cubic root of 166891477 is about 550.5685327686.

The spelling of 166891477 in words is "one hundred sixty-six million, eight hundred ninety-one thousand, four hundred seventy-seven".