21304440396 has 96 divisors (see below), whose sum is σ = 55751942400. Its totient is φ = 7035050880.

The previous prime is 21304440389. The next prime is 21304440397. The reversal of 21304440396 is 69304440312.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21304440396.

It is not an unprimeable number, because it can be changed into a prime (21304440397) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12152256 + ... + 12154008.

It is an arithmetic number, because the mean of its divisors is an integer number (580749400).

Almost surely, 2^21304440396 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 21304440396, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27875971200).

21304440396 is an abundant number, since it is smaller than the sum of its proper divisors (34447502004).

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

21304440396 is a wasteful number, since it uses less digits than its factorization.

21304440396 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2756 (or 2748 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 36.

The spelling of 21304440396 in words is "twenty-one billion, three hundred four million, four hundred forty thousand, three hundred ninety-six".