21213111200 has 72 divisors (see below), whose sum is σ = 52559573472. Its totient is φ = 8358577920.

The previous prime is 21213111169. The next prime is 21213111211. The reversal of 21213111200 is 211131212.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 144284 + ... + 251483.

It is an arithmetic number, because the mean of its divisors is an integer number (729994076).

Almost surely, 2^21213111200 is an apocalyptic number.

21213111200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21213111200 is an abundant number, since it is smaller than the sum of its proper divisors (31346462272).

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

21213111200 is a wasteful number, since it uses less digits than its factorization.

21213111200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 395854 (or 395841 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 21213111200 its reverse (211131212), we get a palindrome (21424242412).

The spelling of 21213111200 in words is "twenty-one billion, two hundred thirteen million, one hundred eleven thousand, two hundred".