21040031244 has 24 divisors (see below), whose sum is σ = 49570044160. Its totient is φ = 6945252624.

The previous prime is 21040031231. The next prime is 21040031261. The reversal of 21040031244 is 44213004012.

It is a self number, because there is not a number n which added to its sum of digits gives 21040031244.

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, 8510104 + ... + 8512575.

Almost surely, 2^21040031244 is an apocalyptic number.

It is an amenable number.

21040031244 is an abundant number, since it is smaller than the sum of its proper divisors (28530012916).

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

21040031244 is a wasteful number, since it uses less digits than its factorization.

21040031244 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17022789 (or 17022787 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

Adding to 21040031244 its reverse (44213004012), we get a palindrome (65253035256).

The spelling of 21040031244 in words is "twenty-one billion, forty million, thirty-one thousand, two hundred forty-four".