21120102320 has 80 divisors (see below), whose sum is σ = 52085693088. Its totient is φ = 7936880640.

The previous prime is 21120102319. The next prime is 21120102323. The reversal of 21120102320 is 2320102112.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 21120102295 and 21120102304.

It is not an unprimeable number, because it can be changed into a prime (21120102323) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 762962 + ... + 790158.

Almost surely, 2^21120102320 is an apocalyptic number.

21120102320 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 21120102320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26042846544).

21120102320 is an abundant number, since it is smaller than the sum of its proper divisors (30965590768).

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

21120102320 is a wasteful number, since it uses less digits than its factorization.

21120102320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27798 (or 27792 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 21120102320 its reverse (2320102112), we get a palindrome (23440204432).

The spelling of 21120102320 in words is "twenty-one billion, one hundred twenty million, one hundred two thousand, three hundred twenty".