21102021212220 has 288 divisors, whose sum is σ = 75716180467200. Its totient is φ = 4707002285568.

The previous prime is 21102021212219. The next prime is 21102021212249. The reversal of 21102021212220 is 2221212020112.

It is a happy number.

21102021212220 is a `hidden beast` number, since 21 + 10 + 202 + 1 + 212 + 220 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21102021212193 and 21102021212202.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 9295450 + ... + 11340609.

It is an arithmetic number, because the mean of its divisors is an integer number (262903404400).

Almost surely, 2^{21102021212220} is an apocalyptic number.

21102021212220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21102021212220 is an abundant number, since it is smaller than the sum of its proper divisors (54614159254980).

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

21102021212220 is a wasteful number, since it uses less digits than its factorization.

21102021212220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20636129 (or 20636124 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21102021212220 its reverse (2221212020112), we get a palindrome (23323233232332).

The spelling of 21102021212220 in words is "twenty-one trillion, one hundred two billion, twenty-one million, two hundred twelve thousand, two hundred twenty".