20553904 has 80 divisors (see below), whose sum is σ = 48568320. Its totient is φ = 8236800.

The previous prime is 20553893. The next prime is 20553931. The reversal of 20553904 is 40935502.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 203454 + ... + 203554.

It is an arithmetic number, because the mean of its divisors is an integer number (607104).

Almost surely, 2^20553904 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20553904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24284160).

20553904 is an abundant number, since it is smaller than the sum of its proper divisors (28014416).

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

20553904 is a wasteful number, since it uses less digits than its factorization.

20553904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218 (or 212 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 28.

The square root of 20553904 is about 4533.6413620841. The cubic root of 20553904 is about 273.9248555190.

The spelling of 20553904 in words is "twenty million, five hundred fifty-three thousand, nine hundred four".