21304034440 has 64 divisors (see below), whose sum is σ = 51644900160. Its totient is φ = 7862511360.

The previous prime is 21304034431. The next prime is 21304034447. The reversal of 21304034440 is 4443040312.

It is a super-2 number, since 2×21304034440² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21304034447) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1308027 + ... + 1324213.

It is an arithmetic number, because the mean of its divisors is an integer number (806951565).

Almost surely, 2^21304034440 is an apocalyptic number.

21304034440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21304034440 is an abundant number, since it is smaller than the sum of its proper divisors (30340865720).

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

21304034440 is a wasteful number, since it uses less digits than its factorization.

21304034440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18742 (or 18738 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 25.

Adding to 21304034440 its reverse (4443040312), we get a palindrome (25747074752).

The spelling of 21304034440 in words is "twenty-one billion, three hundred four million, thirty-four thousand, four hundred forty".