21112121020220 has 48 divisors (see below), whose sum is σ = 45718361515008. Its totient is φ = 8184926368320.

The previous prime is 21112121020189. The next prime is 21112121020231. The reversal of 21112121020220 is 2202012121112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 108930866 + ... + 109124505.

It is an arithmetic number, because the mean of its divisors is an integer number (952465864896).

Almost surely, 2^{21112121020220} is an apocalyptic number.

21112121020220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21112121020220 is an abundant number, since it is smaller than the sum of its proper divisors (24606240494788).

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

21112121020220 is a wasteful number, since it uses less digits than its factorization.

21112121020220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218055530 (or 218055528 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21112121020220 its reverse (2202012121112), we get a palindrome (23314133141332).

The spelling of 21112121020220 in words is "twenty-one trillion, one hundred twelve billion, one hundred twenty-one million, twenty thousand, two hundred twenty".