21211220011220 has 24 divisors (see below), whose sum is σ = 45298537653600. Its totient is φ = 8340683122592.

The previous prime is 21211220011217. The next prime is 21211220011249. The reversal of 21211220011220 is 2211002211212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8987803910 + ... + 8987806269.

It is an arithmetic number, because the mean of its divisors is an integer number (1887439068900).

Almost surely, 2^{21211220011220} is an apocalyptic number.

21211220011220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21211220011220 is an abundant number, since it is smaller than the sum of its proper divisors (24087317642380).

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

21211220011220 is a wasteful number, since it uses less digits than its factorization.

21211220011220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17975610247 (or 17975610245 counting only the distinct ones).

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

Adding to 21211220011220 its reverse (2211002211212), we get a palindrome (23422222222432).

The spelling of 21211220011220 in words is "twenty-one trillion, two hundred eleven billion, two hundred twenty million, eleven thousand, two hundred twenty".