20555904 has 64 divisors (see below), whose sum is σ = 55080000. Its totient is φ = 6792192.

The previous prime is 20555897. The next prime is 20555911. The reversal of 20555904 is 40955502.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20555897) and next prime (20555911).

It is a tau number, because it is divible by the number of its divisors (64).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 76282 + ... + 76550.

It is an arithmetic number, because the mean of its divisors is an integer number (860625).

Almost surely, 2^20555904 is an apocalyptic number.

20555904 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 20555904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27540000).

20555904 is an abundant number, since it is smaller than the sum of its proper divisors (34524096).

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

20555904 is a wasteful number, since it uses less digits than its factorization.

20555904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 485 (or 473 counting only the distinct ones).

The product of its (nonzero) digits is 9000, while the sum is 30.

The square root of 20555904 is about 4533.8619299665. The cubic root of 20555904 is about 273.9337399941.

The spelling of 20555904 in words is "twenty million, five hundred fifty-five thousand, nine hundred four".