166681457 has 2 divisors, whose sum is σ = 166681458. Its totient is φ = 166681456.

The previous prime is 166681409. The next prime is 166681477. The reversal of 166681457 is 754186661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 161823841 + 4857616 = 12721^2 + 2204^2 .

It is a cyclic number.

It is not a de Polignac number, because 166681457 - 2⁶ = 166681393 is a prime.

It is not a weakly prime, because it can be changed into another prime (166681477) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83340728 + 83340729.

It is an arithmetic number, because the mean of its divisors is an integer number (83340729).

Almost surely, 2^166681457 is an apocalyptic number.

It is an amenable number.

166681457 is a deficient number, since it is larger than the sum of its proper divisors (1).

166681457 is an equidigital number, since it uses as much as digits as its factorization.

166681457 is an evil number, because the sum of its binary digits is even.

The product of its digits is 241920, while the sum is 44.

The square root of 166681457 is about 12910.5173017970. The cubic root of 166681457 is about 550.3374865358.

The spelling of 166681457 in words is "one hundred sixty-six million, six hundred eighty-one thousand, four hundred fifty-seven".