21097843200 has 1680 divisors, whose sum is σ = 99827449920. Its totient is φ = 4299816960.

The previous prime is 21097843199. The next prime is 21097843211. The reversal of 21097843200 is 234879012.

21097843200 is a `hidden beast` number, since 210 + 9 + 7 + 8 + 432 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1680).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 167 ways as a sum of consecutive naturals, for example, 1110412791 + ... + 1110412809.

Almost surely, 2^21097843200 is an apocalyptic number.

21097843200 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 21097843200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49913724960).

21097843200 is an abundant number, since it is smaller than the sum of its proper divisors (78729606720).

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

21097843200 is an equidigital number, since it uses as much as digits as its factorization.

21097843200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89 (or 53 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The spelling of 21097843200 in words is "twenty-one billion, ninety-seven million, eight hundred forty-three thousand, two hundred".