21221523051200 has 168 divisors, whose sum is σ = 53502912521520. Its totient is φ = 8279853465600.

The previous prime is 21221523051199. The next prime is 21221523051251. The reversal of 21221523051200 is 215032512212.

It is a happy number.

It is a super-2 number, since 2×21221523051200² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21221523051200.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 343253891 + ... + 343315709.

It is an arithmetic number, because the mean of its divisors is an integer number (318469717390).

Almost surely, 2^{21221523051200} is an apocalyptic number.

21221523051200 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 21221523051200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26751456260760).

21221523051200 is an abundant number, since it is smaller than the sum of its proper divisors (32281389470320).

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

21221523051200 is a wasteful number, since it uses less digits than its factorization.

21221523051200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67115 (or 67100 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 26.

Adding to 21221523051200 its reverse (215032512212), we get a palindrome (21436555563412).

The spelling of 21221523051200 in words is "twenty-one trillion, two hundred twenty-one billion, five hundred twenty-three million, fifty-one thousand, two hundred".