20899956 has 48 divisors (see below), whose sum is σ = 60802560. Its totient is φ = 5428320.

The previous prime is 20899951. The next prime is 20899961. The reversal of 20899956 is 65999802.

It is an interprime number because it is at equal distance from previous prime (20899951) and next prime (20899961).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20899951) 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, 10386 + ... + 12233.

It is an arithmetic number, because the mean of its divisors is an integer number (1266720).

Almost surely, 2^20899956 is an apocalyptic number.

It is an amenable number.

20899956 is an abundant number, since it is smaller than the sum of its proper divisors (39902604).

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

20899956 is a wasteful number, since it uses less digits than its factorization.

20899956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22644 (or 22642 counting only the distinct ones).

The product of its (nonzero) digits is 349920, while the sum is 48.

The square root of 20899956 is about 4571.6469679974. The cubic root of 20899956 is about 275.4536029016.

The spelling of 20899956 in words is "twenty million, eight hundred ninety-nine thousand, nine hundred fifty-six".