21031322320 has 20 divisors (see below), whose sum is σ = 48897824580. Its totient is φ = 8412528896.

The previous prime is 21031322293. The next prime is 21031322327. The reversal of 21031322320 is 2322313012.

It can be written as a sum of positive squares in 2 ways, for example, as 8840512576 + 12190809744 = 94024^2 + 110412^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21031322327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 131445685 + ... + 131445844.

It is an arithmetic number, because the mean of its divisors is an integer number (2444891229).

Almost surely, 2^21031322320 is an apocalyptic number.

21031322320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21031322320 is an abundant number, since it is smaller than the sum of its proper divisors (27866502260).

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

21031322320 is a wasteful number, since it uses less digits than its factorization.

21031322320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 262891542 (or 262891536 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 19.

Adding to 21031322320 its reverse (2322313012), we get a palindrome (23353635332).

The spelling of 21031322320 in words is "twenty-one billion, thirty-one million, three hundred twenty-two thousand, three hundred twenty".