21244304400 has 120 divisors (see below), whose sum is σ = 74239233504. Its totient is φ = 5150131200.

The previous prime is 21244304387. The next prime is 21244304429. The reversal of 21244304400 is 440344212.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 791509 + ... + 817908.

Almost surely, 2^21244304400 is an apocalyptic number.

21244304400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21244304400 is an abundant number, since it is smaller than the sum of its proper divisors (52994929104).

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

21244304400 is a wasteful number, since it uses less digits than its factorization.

21244304400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1609449 (or 1609438 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 24.

Adding to 21244304400 its reverse (440344212), we get a palindrome (21684648612).

The spelling of 21244304400 in words is "twenty-one billion, two hundred forty-four million, three hundred four thousand, four hundred".