21101222320 has 80 divisors (see below), whose sum is σ = 50363026560. Its totient is φ = 8219308032.

The previous prime is 21101222291. The next prime is 21101222357. The reversal of 21101222320 is 2322210112.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a junction number, because it is equal to n+sod(n) for n = 21101222294 and 21101222303.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 438492 + ... + 484228.

It is an arithmetic number, because the mean of its divisors is an integer number (629537832).

Almost surely, 2^21101222320 is an apocalyptic number.

21101222320 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 21101222320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25181513280).

21101222320 is an abundant number, since it is smaller than the sum of its proper divisors (29261804240).

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

21101222320 is a wasteful number, since it uses less digits than its factorization.

21101222320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45902 (or 45896 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21101222320 its reverse (2322210112), we get a palindrome (23423432432).

It can be divided in two parts, 211012 and 22320, that added together give a palindrome (233332).

The spelling of 21101222320 in words is "twenty-one billion, one hundred one million, two hundred twenty-two thousand, three hundred twenty".