21320244032 has 42 divisors (see below), whose sum is σ = 43364632854. Its totient is φ = 10400066560.

The previous prime is 21320243927. The next prime is 21320244037. The reversal of 21320244032 is 23044202312.

It can be written as a sum of positive squares in 3 ways, for example, as 220938496 + 21099305536 = 14864^2 + 145256^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21320243989 and 21320244007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21320244037) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8498 + ... + 206670.

Almost surely, 2^21320244032 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21320244032, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21682316427).

21320244032 is an abundant number, since it is smaller than the sum of its proper divisors (22044388822).

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

21320244032 is an equidigital number, since it uses as much as digits as its factorization.

21320244032 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198267 (or 198216 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 23.

Adding to 21320244032 its reverse (23044202312), we get a palindrome (44364446344).

The spelling of 21320244032 in words is "twenty-one billion, three hundred twenty million, two hundred forty-four thousand, thirty-two".