21121200221020 has 24 divisors (see below), whose sum is σ = 44354644823664. Its totient is φ = 8448456400896.

The previous prime is 21121200220973. The next prime is 21121200221027. The reversal of 21121200221020 is 2012200212112.

It is a happy number.

It is a super-2 number, since 2×21121200221020² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21121200220985 and 21121200221003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121200221027) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7022172 + ... + 9568348.

It is an arithmetic number, because the mean of its divisors is an integer number (1848110200986).

Almost surely, 2^{21121200221020} is an apocalyptic number.

21121200221020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21121200221020 is an abundant number, since it is smaller than the sum of its proper divisors (23233444602644).

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

21121200221020 is a wasteful number, since it uses less digits than its factorization.

21121200221020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2960949 (or 2960947 counting only the distinct ones).

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

Adding to 21121200221020 its reverse (2012200212112), we get a palindrome (23133400433132).

The spelling of 21121200221020 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred million, two hundred twenty-one thousand, twenty".