21003311244 has 24 divisors (see below), whose sum is σ = 50203037808. Its totient is φ = 6830344960.

The previous prime is 21003311233. The next prime is 21003311267. The reversal of 21003311244 is 44211330012.

It is a super-2 number, since 2×21003311244² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21003311244.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21344337 + ... + 21345320.

It is an arithmetic number, because the mean of its divisors is an integer number (2091793242).

Almost surely, 2^21003311244 is an apocalyptic number.

It is an amenable number.

21003311244 is an abundant number, since it is smaller than the sum of its proper divisors (29199726564).

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

21003311244 is a wasteful number, since it uses less digits than its factorization.

21003311244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42689705 (or 42689703 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

Adding to 21003311244 its reverse (44211330012), we get a palindrome (65214641256).

The spelling of 21003311244 in words is "twenty-one billion, three million, three hundred eleven thousand, two hundred forty-four".