21111212010220 has 48 divisors (see below), whose sum is σ = 44368753631328. Its totient is φ = 8437779694080.

The previous prime is 21111212010193. The next prime is 21111212010223. The reversal of 21111212010220 is 2201021211112.

It is a junction number, because it is equal to n+sod(n) for n = 21111212010194 and 21111212010203.

It is not an unprimeable number, because it can be changed into a prime (21111212010223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 320411680 + ... + 320477560.

It is an arithmetic number, because the mean of its divisors is an integer number (924349033986).

Almost surely, 2^{21111212010220} is an apocalyptic number.

21111212010220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21111212010220 is an abundant number, since it is smaller than the sum of its proper divisors (23257541621108).

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

21111212010220 is a wasteful number, since it uses less digits than its factorization.

21111212010220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78370 (or 78368 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21111212010220 its reverse (2201021211112), we get a palindrome (23312233221332).

The spelling of 21111212010220 in words is "twenty-one trillion, one hundred eleven billion, two hundred twelve million, ten thousand, two hundred twenty".