21210311123320 has 128 divisors (see below), whose sum is σ = 52557351344640. Its totient is φ = 7639431600640.

The previous prime is 21210311123249. The next prime is 21210311123321. The reversal of 21210311123320 is 2332111301212.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a junction number, because it is equal to n+sod(n) for n = 21210311123291 and 21210311123300.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210311123321) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 294826074 + ... + 294898006.

It is an arithmetic number, because the mean of its divisors is an integer number (410604307380).

Almost surely, 2^{21210311123320} is an apocalyptic number.

21210311123320 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 21210311123320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26278675672320).

21210311123320 is an abundant number, since it is smaller than the sum of its proper divisors (31347040221320).

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

21210311123320 is a wasteful number, since it uses less digits than its factorization.

21210311123320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78325 (or 78321 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 22.

Adding to 21210311123320 its reverse (2332111301212), we get a palindrome (23542422424532).

The spelling of 21210311123320 in words is "twenty-one trillion, two hundred ten billion, three hundred eleven million, one hundred twenty-three thousand, three hundred twenty".