21200988 has 12 divisors (see below), whose sum is σ = 49469000. Its totient is φ = 7066992.

The previous prime is 21200987. The next prime is 21201031. The reversal of 21200988 is 88900212.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×21200988² = 898963784352288, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 883363 + ... + 883386.

Almost surely, 2^21200988 is an apocalyptic number.

It is an amenable number.

21200988 is an abundant number, since it is smaller than the sum of its proper divisors (28268012).

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

21200988 is a wasteful number, since it uses less digits than its factorization.

21200988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1766756 (or 1766754 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 21200988 is about 4604.4530619825. The cubic root of 21200988 is about 276.7698001010.

The spelling of 21200988 in words is "twenty-one million, two hundred thousand, nine hundred eighty-eight".