168999999 has 16 divisors (see below), whose sum is σ = 257959680. Its totient is φ = 96408000.

The previous prime is 168999997. The next prime is 169000033. The reversal of 168999999 is 999999861.

It is a Cunningham number, because it is equal to 13000²-1.

It is not a de Polignac number, because 168999999 - 2¹ = 168999997 is a prime.

168999999 is a modest number, since divided by 99999 gives 1689 as remainder.

It is a plaindrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (168999997) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6499 + ... + 19499.

It is an arithmetic number, because the mean of its divisors is an integer number (16122480).

Almost surely, 2^168999999 is an apocalyptic number.

168999999 is a deficient number, since it is larger than the sum of its proper divisors (88959681).

168999999 is a wasteful number, since it uses less digits than its factorization.

168999999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13630.

The product of its digits is 25509168, while the sum is 69.

The square root of 168999999 is about 12999.9999615385. Note that the first 4 decimals coincide. The cubic root of 168999999 is about 552.8774802774.

The spelling of 168999999 in words is "one hundred sixty-eight million, nine hundred ninety-nine thousand, nine hundred ninety-nine".