21212202221220 has 96 divisors (see below), whose sum is σ = 60450205939200. Its totient is φ = 5556265090560.

The previous prime is 21212202221183. The next prime is 21212202221291. The reversal of 21212202221220 is 2212220221212.

It is a super-4 number, since 4×21212202221220⁴ (a number of 54 digits) contains 4444 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1270620 + ... + 6636179.

It is an arithmetic number, because the mean of its divisors is an integer number (629689645200).

Almost surely, 2^{21212202221220} is an apocalyptic number.

21212202221220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21212202221220 is an abundant number, since it is smaller than the sum of its proper divisors (39238003717980).

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

21212202221220 is a wasteful number, since it uses less digits than its factorization.

21212202221220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7907605 (or 7907603 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 21.

Adding to 21212202221220 its reverse (2212220221212), we get a palindrome (23424422442432).

The spelling of 21212202221220 in words is "twenty-one trillion, two hundred twelve billion, two hundred two million, two hundred twenty-one thousand, two hundred twenty".