20211211111220 has 96 divisors (see below), whose sum is σ = 44147086663680. Its totient is φ = 7763078059520.

The previous prime is 20211211111193. The next prime is 20211211111243. The reversal of 20211211111220 is 2211111211202.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 306983705 + ... + 307049535.

It is an arithmetic number, because the mean of its divisors is an integer number (459865486080).

Almost surely, 2^{20211211111220} is an apocalyptic number.

20211211111220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20211211111220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22073543331840).

20211211111220 is an abundant number, since it is smaller than the sum of its proper divisors (23935875552460).

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

20211211111220 is a wasteful number, since it uses less digits than its factorization.

20211211111220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68753 (or 68751 counting only the distinct ones).

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

Adding to 20211211111220 its reverse (2211111211202), we get a palindrome (22422322322422).

The spelling of 20211211111220 in words is "twenty trillion, two hundred eleven billion, two hundred eleven million, one hundred eleven thousand, two hundred twenty".