20168904 has 64 divisors (see below), whose sum is σ = 57968640. Its totient is φ = 5728320.

The previous prime is 20168903. The next prime is 20168909. The reversal of 20168904 is 40986102.

It is a super-2 number, since 2×20168904² = 813569377122432, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20168903) 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, 45307 + ... + 45749.

It is an arithmetic number, because the mean of its divisors is an integer number (905760).

Almost surely, 2^20168904 is an apocalyptic number.

20168904 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20168904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28984320).

20168904 is an abundant number, since it is smaller than the sum of its proper divisors (37799736).

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

20168904 is a wasteful number, since it uses less digits than its factorization.

20168904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 730 (or 726 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 20168904 is about 4490.9802938779. The cubic root of 20168904 is about 272.2037472831.

The spelling of 20168904 in words is "twenty million, one hundred sixty-eight thousand, nine hundred four".