21303121320 has 192 divisors, whose sum is σ = 75246771600. Its totient is φ = 5195612160.

The previous prime is 21303121319. The next prime is 21303121321. The reversal of 21303121320 is 2312130312.

21303121320 is a `hidden beast` number, since 2 + 1 + 30 + 312 + 1 + 320 = 666.

It is an interprime number because it is at equal distance from previous prime (21303121319) and next prime (21303121321).

It can be written as a sum of positive squares in 8 ways, for example, as 1118099844 + 20185021476 = 33438^2 + 142074^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21303121293 and 21303121302.

It is not an unprimeable number, because it can be changed into a prime (21303121321) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 489240 + ... + 531000.

Almost surely, 2^21303121320 is an apocalyptic number.

21303121320 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 21303121320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37623385800).

21303121320 is an abundant number, since it is smaller than the sum of its proper divisors (53943650280).

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

21303121320 is a wasteful number, since it uses less digits than its factorization.

21303121320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41900 (or 41893 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21303121320 its reverse (2312130312), we get a palindrome (23615251632).

The spelling of 21303121320 in words is "twenty-one billion, three hundred three million, one hundred twenty-one thousand, three hundred twenty".