21020947200 has 432 divisors, whose sum is σ = 84096700800. Its totient is φ = 5095526400.

The previous prime is 21020947193. The next prime is 21020947223. The reversal of 21020947200 is 274902012.

21020947200 is a `hidden beast` number, since 210 + 209 + 47 + 200 = 666.

It is a tau number, because it is divible by the number of its divisors (432).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1895271 + ... + 1906329.

Almost surely, 2^21020947200 is an apocalyptic number.

21020947200 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 21020947200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42048350400).

21020947200 is an abundant number, since it is smaller than the sum of its proper divisors (63075753600).

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

21020947200 is a wasteful number, since it uses less digits than its factorization.

21020947200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11105 (or 11080 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The spelling of 21020947200 in words is "twenty-one billion, twenty million, nine hundred forty-seven thousand, two hundred".