21212440004 has 48 divisors (see below), whose sum is σ = 42855740928. Its totient is φ = 8998929408.

The previous prime is 21212439959. The next prime is 21212440019. The reversal of 21212440004 is 40004421212.

It is a super-2 number, since 2×21212440004² (a number of 21 digits) contains 22 as substring.

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, 2707637 + ... + 2715459.

It is an arithmetic number, because the mean of its divisors is an integer number (892827936).

Almost surely, 2^21212440004 is an apocalyptic number.

It is an amenable number.

21212440004 is an abundant number, since it is smaller than the sum of its proper divisors (21643300924).

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

21212440004 is a wasteful number, since it uses less digits than its factorization.

21212440004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8804 (or 8802 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 20.

Adding to 21212440004 its reverse (40004421212), we get a palindrome (61216861216).

The spelling of 21212440004 in words is "twenty-one billion, two hundred twelve million, four hundred forty thousand, four".