166487409 has 81 divisors (see below), whose sum is σ = 293534059. Its totient is φ = 90837120.

The previous prime is 166487381. The next prime is 166487411. The reversal of 166487409 is 904784661.

The square root of 166487409 is 12903.

It is a perfect power (a square), and thus also a powerful number.

166487409 is a `hidden beast` number, since 166 + 4 + 87 + 409 = 666.

It can be written as a sum of positive squares in only one way, i.e., 129618225 + 36869184 = 11385^2 + 6072^2 .

It is not a de Polignac number, because 166487409 - 2¹⁵ = 166454641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166487509) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 7238572 + ... + 7238594.

Almost surely, 2^166487409 is an apocalyptic number.

166487409 is the 12903-rd square number.

166487409 is the 6452-nd centered octagonal number.

It is an amenable number.

166487409 is a deficient number, since it is larger than the sum of its proper divisors (127046650).

166487409 is a wasteful number, since it uses less digits than its factorization.

166487409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108 (or 54 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The cubic root of 166487409 is about 550.1238387809.

The spelling of 166487409 in words is "one hundred sixty-six million, four hundred eighty-seven thousand, four hundred nine".