166581864 has 48 divisors (see below), whose sum is σ = 451803300. Its totient is φ = 55448064.

The previous prime is 166581823. The next prime is 166581869. The reversal of 166581864 is 468185661.

166581864 is a `hidden beast` number, since 1 + 6 + 6 + 581 + 8 + 64 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 159516900 + 7064964 = 12630^2 + 2658^2 .

It is not an unprimeable number, because it can be changed into a prime (166581869) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 71502 + ... + 73794.

Almost surely, 2^166581864 is an apocalyptic number.

It is an amenable number.

166581864 is an abundant number, since it is smaller than the sum of its proper divisors (285221436).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

166581864 is a wasteful number, since it uses less digits than its factorization.

166581864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3314 (or 3307 counting only the distinct ones).

The product of its digits is 276480, while the sum is 45.

The square root of 166581864 is about 12906.6596763066. The cubic root of 166581864 is about 550.2278549022.

The spelling of 166581864 in words is "one hundred sixty-six million, five hundred eighty-one thousand, eight hundred sixty-four".