21968821392 has 160 divisors (see below), whose sum is σ = 67698167040. Its totient is φ = 6007971840.

The previous prime is 21968821361. The next prime is 21968821403. The reversal of 21968821392 is 29312886912.

It is a super-2 number, since 2×21968821392² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 715084 + ... + 745172.

It is an arithmetic number, because the mean of its divisors is an integer number (423113544).

Almost surely, 2^21968821392 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 21968821392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33849083520).

21968821392 is an abundant number, since it is smaller than the sum of its proper divisors (45729345648).

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

21968821392 is a wasteful number, since it uses less digits than its factorization.

21968821392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30201 (or 30195 counting only the distinct ones).

The product of its digits is 746496, while the sum is 51.

The spelling of 21968821392 in words is "twenty-one billion, nine hundred sixty-eight million, eight hundred twenty-one thousand, three hundred ninety-two".