21504044212 has 24 divisors (see below), whose sum is σ = 44878006656. Its totient is φ = 8815322208.

The previous prime is 21504044207. The next prime is 21504044213. The reversal of 21504044212 is 21244040512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21504044213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16695043 + ... + 16696330.

It is an arithmetic number, because the mean of its divisors is an integer number (1869916944).

Almost surely, 2^21504044212 is an apocalyptic number.

It is an amenable number.

21504044212 is an abundant number, since it is smaller than the sum of its proper divisors (23373962444).

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

21504044212 is a wasteful number, since it uses less digits than its factorization.

21504044212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33391407 (or 33391405 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 25.

Adding to 21504044212 its reverse (21244040512), we get a palindrome (42748084724).

The spelling of 21504044212 in words is "twenty-one billion, five hundred four million, forty-four thousand, two hundred twelve".