21211222221200 has 480 divisors, whose sum is σ = 56800113560064. Its totient is φ = 7610803200000.

The previous prime is 21211222221191. The next prime is 21211222221209. The reversal of 21211222221200 is 212222211212.

It is an interprime number because it is at equal distance from previous prime (21211222221191) and next prime (21211222221209).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (21211222221209) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 23283448745 + ... + 23283449655.

Almost surely, 2^{21211222221200} is an apocalyptic number.

21211222221200 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 21211222221200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28400056780032).

21211222221200 is an abundant number, since it is smaller than the sum of its proper divisors (35588891338864).

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

21211222221200 is a wasteful number, since it uses less digits than its factorization.

21211222221200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1496 (or 1463 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 21211222221200 its reverse (212222211212), we get a palindrome (21423444432412).

The spelling of 21211222221200 in words is "twenty-one trillion, two hundred eleven billion, two hundred twenty-two million, two hundred twenty-one thousand, two hundred".