168405999129 has 21 divisors (see below), whose sum is σ = 252510107493. Its totient is φ = 112263279372.

The previous prime is 168405999079. The next prime is 168405999163. The reversal of 168405999129 is 921999504861.

The square root of 168405999129 is 410373.

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

168405999129 is a `hidden beast` number, since 16 + 8 + 4 + 0 + 599 + 9 + 1 + 29 = 666.

It is not a de Polignac number, because 168405999129 - 2⁷ = 168405999001 is a prime.

It is not an unprimeable number, because it can be changed into a prime (168405999169) by changing a digit.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 11072472 + ... + 11087670.

It is an arithmetic number, because the mean of its divisors is an integer number (12024290833).

Almost surely, 2^168405999129 is an apocalyptic number.

168405999129 is the 410373-rd square number.

168405999129 is the 205187-th centered octagonal number.

It is an amenable number.

168405999129 is a deficient number, since it is larger than the sum of its proper divisors (84104108364).

168405999129 is an frugal number, since it uses more digits than its factorization.

168405999129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30416 (or 15202 counting only the distinct ones).

The product of its (nonzero) digits is 12597120, while the sum is 63.

The spelling of 168405999129 in words is "one hundred sixty-eight billion, four hundred five million, nine hundred ninety-nine thousand, one hundred twenty-nine".