21423020320 has 48 divisors (see below), whose sum is σ = 54505112760. Its totient is φ = 7910037504.

The previous prime is 21423020317. The next prime is 21423020329. The reversal of 21423020320 is 2302032412.

It can be written as a sum of positive squares in 4 ways, for example, as 13224080016 + 8198940304 = 114996^2 + 90548^2 .

It is a super-2 number, since 2×21423020320² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21423020329) 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, 5147685 + ... + 5151844.

Almost surely, 2^21423020320 is an apocalyptic number.

21423020320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21423020320 is an abundant number, since it is smaller than the sum of its proper divisors (33082092440).

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

21423020320 is a wasteful number, since it uses less digits than its factorization.

21423020320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10299557 (or 10299549 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 19.

Adding to 21423020320 its reverse (2302032412), we get a palindrome (23725052732).

The spelling of 21423020320 in words is "twenty-one billion, four hundred twenty-three million, twenty thousand, three hundred twenty".