21112122211220 has 96 divisors (see below), whose sum is σ = 46725821049600. Its totient is φ = 8001407361024.

The previous prime is 21112122211217. The next prime is 21112122211273. The reversal of 21112122211220 is 2211222121112.

It is a super-2 number, since 2×21112122211220² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 21112122211192 and 21112122211201.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9187316 + ... + 11253044.

It is an arithmetic number, because the mean of its divisors is an integer number (486727302600).

Almost surely, 2^{21112122211220} is an apocalyptic number.

21112122211220 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 21112122211220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23362910524800).

21112122211220 is an abundant number, since it is smaller than the sum of its proper divisors (25613698838380).

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

21112122211220 is a wasteful number, since it uses less digits than its factorization.

21112122211220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2066097 (or 2066095 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 21112122211220 its reverse (2211222121112), we get a palindrome (23323344332332).

The spelling of 21112122211220 in words is "twenty-one trillion, one hundred twelve billion, one hundred twenty-two million, two hundred eleven thousand, two hundred twenty".