21040340024 has 16 divisors (see below), whose sum is σ = 43037059320. Its totient is φ = 9563790880.

The previous prime is 21040340017. The next prime is 21040340033. The reversal of 21040340024 is 42004304012.

It is a junction number, because it is equal to n+sod(n) for n = 21040339978 and 21040340005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 119547299 + ... + 119547474.

Almost surely, 2^21040340024 is an apocalyptic number.

It is an amenable number.

21040340024 is an abundant number, since it is smaller than the sum of its proper divisors (21996719296).

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

21040340024 is a wasteful number, since it uses less digits than its factorization.

21040340024 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239094790 (or 239094786 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

Adding to 21040340024 its reverse (42004304012), we get a palindrome (63044644036).

The spelling of 21040340024 in words is "twenty-one billion, forty million, three hundred forty thousand, twenty-four".