21240302004 has 48 divisors (see below), whose sum is σ = 55572686400. Its totient is φ = 7015141728.

The previous prime is 21240301991. The next prime is 21240302081. The reversal of 21240302004 is 40020304212.

It is a super-2 number, since 2×21240302004² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 890382 + ... + 913925.

It is an arithmetic number, because the mean of its divisors is an integer number (1157764300).

Almost surely, 2^21240302004 is an apocalyptic number.

It is an amenable number.

21240302004 is an abundant number, since it is smaller than the sum of its proper divisors (34332384396).

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

21240302004 is a wasteful number, since it uses less digits than its factorization.

21240302004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1804429 (or 1804421 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

Adding to 21240302004 its reverse (40020304212), we get a palindrome (61260606216).

The spelling of 21240302004 in words is "twenty-one billion, two hundred forty million, three hundred two thousand, four".