21468823816 has 24 divisors (see below), whose sum is σ = 44246183310. Its totient is φ = 9758555840.

The previous prime is 21468823811. The next prime is 21468823837. The reversal of 21468823816 is 61832886412.

It can be written as a sum of positive squares in only one way, i.e., 12623421316 + 8845402500 = 112354^2 + 94050^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21468823816.

It is not an unprimeable number, because it can be changed into a prime (21468823811) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11088301 + ... + 11090236.

Almost surely, 2^21468823816 is an apocalyptic number.

It is an amenable number.

21468823816 is an abundant number, since it is smaller than the sum of its proper divisors (22777359494).

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

21468823816 is a wasteful number, since it uses less digits than its factorization.

21468823816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22178565 (or 22178550 counting only the distinct ones).

The product of its digits is 884736, while the sum is 49.

The spelling of 21468823816 in words is "twenty-one billion, four hundred sixty-eight million, eight hundred twenty-three thousand, eight hundred sixteen".