21020221121200 has 240 divisors, whose sum is σ = 59156970211584. Its totient is φ = 7029069696000.

The previous prime is 21020221121167. The next prime is 21020221121213. The reversal of 21020221121200 is 212112202012.

It is a happy number.

It is a super-3 number, since 3×21020221121200³ (a number of 41 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 18392907 + ... + 19502293.

Almost surely, 2^{21020221121200} is an apocalyptic number.

21020221121200 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 21020221121200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29578485105792).

21020221121200 is an abundant number, since it is smaller than the sum of its proper divisors (38136749090384).

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

21020221121200 is a wasteful number, since it uses less digits than its factorization.

21020221121200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1109580 (or 1109569 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21020221121200 its reverse (212112202012), we get a palindrome (21232333323212).

The spelling of 21020221121200 in words is "twenty-one trillion, twenty billion, two hundred twenty-one million, one hundred twenty-one thousand, two hundred".