21992100 has 72 divisors (see below), whose sum is σ = 68537280. Its totient is φ = 5412480.

The previous prime is 21992083. The next prime is 21992129. The reversal of 21992100 is 129912.

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, 1081 + ... + 6719.

Almost surely, 2^21992100 is an apocalyptic number.

21992100 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 21992100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34268640).

21992100 is an abundant number, since it is smaller than the sum of its proper divisors (46545180).

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

21992100 is a wasteful number, since it uses less digits than its factorization.

21992100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5669 (or 5662 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 24.

The square root of 21992100 is about 4689.5735413788. The cubic root of 21992100 is about 280.1703894885.

The spelling of 21992100 in words is "twenty-one million, nine hundred ninety-two thousand, one hundred".