166640450405 has 24 divisors (see below), whose sum is σ = 236707844856. Its totient is φ = 111870506880.

The previous prime is 166640450401. The next prime is 166640450411. The reversal of 166640450405 is 504054046661.

It can be written as a sum of positive squares in 4 ways, for example, as 2804126116 + 163836324289 = 52954^2 + 404767^2 .

It is not a de Polignac number, because 166640450405 - 2² = 166640450401 is a prime.

It is a super-2 number, since 2×166640450405² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166640450401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10585934 + ... + 10601663.

It is an arithmetic number, because the mean of its divisors is an integer number (9862826869).

Almost surely, 2^166640450405 is an apocalyptic number.

It is an amenable number.

166640450405 is a deficient number, since it is larger than the sum of its proper divisors (70067394451).

166640450405 is a wasteful number, since it uses less digits than its factorization.

166640450405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21187637 (or 21187626 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 41.

The spelling of 166640450405 in words is "one hundred sixty-six billion, six hundred forty million, four hundred fifty thousand, four hundred five".