20563900 has 72 divisors (see below), whose sum is σ = 52809120. Its totient is φ = 6800640.

The previous prime is 20563891. The next prime is 20563913. The reversal of 20563900 is 936502.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19794 + ... + 20806.

It is an arithmetic number, because the mean of its divisors is an integer number (733460).

Almost surely, 2^20563900 is an apocalyptic number.

20563900 is a gapful number since it is divisible by the number (20) 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 20563900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26404560).

20563900 is an abundant number, since it is smaller than the sum of its proper divisors (32245220).

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

20563900 is a wasteful number, since it uses less digits than its factorization.

20563900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1063 (or 1056 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 25.

The square root of 20563900 is about 4534.7436531738. The cubic root of 20563900 is about 273.9692543689.

The spelling of 20563900 in words is "twenty million, five hundred sixty-three thousand, nine hundred".