21204423244 has 48 divisors (see below), whose sum is σ = 39609400320. Its totient is φ = 9904118400.

The previous prime is 21204423241. The next prime is 21204423287. The reversal of 21204423244 is 44232440212.

It is a super-2 number, since 2×21204423244² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21204423241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1565469 + ... + 1578955.

It is an arithmetic number, because the mean of its divisors is an integer number (825195840).

Almost surely, 2^21204423244 is an apocalyptic number.

It is an amenable number.

21204423244 is a deficient number, since it is larger than the sum of its proper divisors (18404977076).

21204423244 is a wasteful number, since it uses less digits than its factorization.

21204423244 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13798 (or 13796 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 28.

Adding to 21204423244 its reverse (44232440212), we get a palindrome (65436863456).

The spelling of 21204423244 in words is "twenty-one billion, two hundred four million, four hundred twenty-three thousand, two hundred forty-four".