21121223011200 has 576 divisors, whose sum is σ = 82140684378480. Its totient is φ = 5136423321600.

The previous prime is 21121223011199. The next prime is 21121223011237. The reversal of 21121223011200 is 211032212112.

21121223011200 is a `hidden beast` number, since 2 + 11 + 212 + 230 + 11 + 200 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

It is a super-2 number, since 2×21121223011200² (a number of 27 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 30735360 + ... + 31415040.

Almost surely, 2^{21121223011200} is an apocalyptic number.

21121223011200 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 21121223011200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41070342189240).

21121223011200 is an abundant number, since it is smaller than the sum of its proper divisors (61019461367280).

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

21121223011200 is a wasteful number, since it uses less digits than its factorization.

21121223011200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 679807 (or 679787 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 21121223011200 its reverse (211032212112), we get a palindrome (21332255223312).

The spelling of 21121223011200 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred twenty-three million, eleven thousand, two hundred".