21373282368 has 168 divisors, whose sum is σ = 64959862968. Its totient is φ = 6695682048.

The previous prime is 21373282339. The next prime is 21373282369. The reversal of 21373282368 is 86328237312.

21373282368 is a `hidden beast` number, since 2 + 1 + 3 + 7 + 3 + 282 + 368 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 4252083264 + 17121199104 = 65208^2 + 130848^2 .

It is not an unprimeable number, because it can be changed into a prime (21373282369) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10114080 + ... + 10116192.

It is an arithmetic number, because the mean of its divisors is an integer number (386665851).

Almost surely, 2^21373282368 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 21373282368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32479931484).

21373282368 is an abundant number, since it is smaller than the sum of its proper divisors (43586580600).

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

21373282368 is a wasteful number, since it uses less digits than its factorization.

21373282368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3181 (or 3168 counting only the distinct ones).

The product of its digits is 580608, while the sum is 45.

The spelling of 21373282368 in words is "twenty-one billion, three hundred seventy-three million, two hundred eighty-two thousand, three hundred sixty-eight".