21212122021120 has 72 divisors (see below), whose sum is σ = 50867336446920. Its totient is φ = 8475217428480.

The previous prime is 21212122021117. The next prime is 21212122021127. The reversal of 21212122021120 is 2112022121212.

It can be written as a sum of positive squares in 4 ways, for example, as 126098850816 + 21086023170304 = 355104^2 + 4591952^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212122021127) 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, 8277525 + ... + 10532884.

It is an arithmetic number, because the mean of its divisors is an integer number (706490783985).

Almost surely, 2^{21212122021120} is an apocalyptic number.

21212122021120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21212122021120 is an abundant number, since it is smaller than the sum of its proper divisors (29655214425800).

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

21212122021120 is an equidigital number, since it uses as much as digits as its factorization.

21212122021120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18811311 (or 18811297 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21212122021120 its reverse (2112022121212), we get a palindrome (23324144142332).

The spelling of 21212122021120 in words is "twenty-one trillion, two hundred twelve billion, one hundred twenty-two million, twenty-one thousand, one hundred twenty".