21211202221200 has 90 divisors (see below), whose sum is σ = 73608763720674. Its totient is φ = 5656320591360.

The previous prime is 21211202221169. The next prime is 21211202221211. The reversal of 21211202221200 is 212220211212.

It is a happy number.

21211202221200 is a `hidden beast` number, since 2 + 121 + 120 + 2 + 221 + 200 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 358791416064 + 20852410805136 = 598992^2 + 4566444^2 .

It is a tau number, because it is divible by the number of its divisors (90).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 2945996709 + ... + 2946003908.

Almost surely, 2^{21211202221200} is an apocalyptic number.

21211202221200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21211202221200 is an abundant number, since it is smaller than the sum of its proper divisors (52397561499474).

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

21211202221200 is a wasteful number, since it uses less digits than its factorization.

21211202221200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5892000641 (or 5892000627 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21211202221200 its reverse (212220211212), we get a palindrome (21423422432412).

The spelling of 21211202221200 in words is "twenty-one trillion, two hundred eleven billion, two hundred two million, two hundred twenty-one thousand, two hundred".