21123335168 has 44 divisors (see below), whose sum is σ = 45474227820. Its totient is φ = 9749225472.

The previous prime is 21123335141. The next prime is 21123335183. The reversal of 21123335168 is 86153332112.

It can be written as a sum of positive squares in 2 ways, for example, as 13597425664 + 7525909504 = 116608^2 + 86752^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 780083 + ... + 806706.

Almost surely, 2^21123335168 is an apocalyptic number.

It is an amenable number.

21123335168 is an abundant number, since it is smaller than the sum of its proper divisors (24350892652).

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

21123335168 is a wasteful number, since it uses less digits than its factorization.

21123335168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1586822 (or 1586804 counting only the distinct ones).

The product of its digits is 25920, while the sum is 35.

The spelling of 21123335168 in words is "twenty-one billion, one hundred twenty-three million, three hundred thirty-five thousand, one hundred sixty-eight".