21099200 has 42 divisors (see below), whose sum is σ = 51921156. Its totient is φ = 8439040.

The previous prime is 21099187. The next prime is 21099277. The reversal of 21099200 is 299012.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4994 + ... + 8193.

It is an arithmetic number, because the mean of its divisors is an integer number (1236218).

Almost surely, 2^21099200 is an apocalyptic number.

21099200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21099200 is an abundant number, since it is smaller than the sum of its proper divisors (30821956).

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

21099200 is a wasteful number, since it uses less digits than its factorization.

21099200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13209 (or 13194 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 21099200 is about 4593.3865502481. The cubic root of 21099200 is about 276.3261564635.

The spelling of 21099200 in words is "twenty-one million, ninety-nine thousand, two hundred".