20859900 has 72 divisors (see below), whose sum is σ = 62329344. Its totient is φ = 5380800.

The previous prime is 20859893. The next prime is 20859953. The reversal of 20859900 is 995802.

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, 8179 + ... + 10421.

Almost surely, 2^20859900 is an apocalyptic number.

20859900 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 20859900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31164672).

20859900 is an abundant number, since it is smaller than the sum of its proper divisors (41469444).

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

20859900 is a wasteful number, since it uses less digits than its factorization.

20859900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2291 (or 2284 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 33.

The square root of 20859900 is about 4567.2639512075. The cubic root of 20859900 is about 275.2775159940.

The spelling of 20859900 in words is "twenty million, eight hundred fifty-nine thousand, nine hundred".