21211101211220 has 12 divisors (see below), whose sum is σ = 44543312543604. Its totient is φ = 8484440484480.

The previous prime is 21211101211217. The next prime is 21211101211229. The reversal of 21211101211220 is 2211210111212.

It can be written as a sum of positive squares in 2 ways, for example, as 16387226956996 + 4823874254224 = 4048114^2 + 2196332^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211101211229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 530277530261 + ... + 530277530300.

It is an arithmetic number, because the mean of its divisors is an integer number (3711942711967).

Almost surely, 2^{21211101211220} is an apocalyptic number.

21211101211220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21211101211220 is an abundant number, since it is smaller than the sum of its proper divisors (23332211332384).

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

21211101211220 is a wasteful number, since it uses less digits than its factorization.

21211101211220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1060555060570 (or 1060555060568 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 21211101211220 its reverse (2211210111212), we get a palindrome (23422311322432).

The spelling of 21211101211220 in words is "twenty-one trillion, two hundred eleven billion, one hundred one million, two hundred eleven thousand, two hundred twenty".