21228685996 has 48 divisors (see below), whose sum is σ = 43475466496. Its totient is φ = 8880145344.

The previous prime is 21228685963. The next prime is 21228686021. The reversal of 21228685996 is 69958682212.

It is a self number, because there is not a number n which added to its sum of digits gives 21228685996.

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, 1953490 + ... + 1964326.

Almost surely, 2^21228685996 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21228685996, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21737733248).

21228685996 is an abundant number, since it is smaller than the sum of its proper divisors (22246780500).

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

21228685996 is a wasteful number, since it uses less digits than its factorization.

21228685996 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12518 (or 12516 counting only the distinct ones).

The product of its digits is 7464960, while the sum is 58.

The spelling of 21228685996 in words is "twenty-one billion, two hundred twenty-eight million, six hundred eighty-five thousand, nine hundred ninety-six".