21023513320 has 32 divisors (see below), whose sum is σ = 47473698600. Its totient is φ = 8379042048.

The previous prime is 21023513311. The next prime is 21023513323. The reversal of 21023513320 is 2331532012.

It can be written as a sum of positive squares in 4 ways, for example, as 10087791844 + 10935721476 = 100438^2 + 104574^2 .

It is a super-2 number, since 2×21023513320² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21023513291 and 21023513300.

It is not an unprimeable number, because it can be changed into a prime (21023513323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 937635 + ... + 959794.

Almost surely, 2^21023513320 is an apocalyptic number.

21023513320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21023513320 is an abundant number, since it is smaller than the sum of its proper divisors (26450185280).

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

21023513320 is a wasteful number, since it uses less digits than its factorization.

21023513320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1897717 (or 1897713 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 22.

The spelling of 21023513320 in words is "twenty-one billion, twenty-three million, five hundred thirteen thousand, three hundred twenty".