21878304768 has 364 divisors, whose sum is σ = 69616685088. Its totient is φ = 6847856640.

The previous prime is 21878304757. The next prime is 21878304781. The reversal of 21878304768 is 86740387812.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 50761513 + ... + 50761943.

Almost surely, 2^21878304768 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 21878304768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34808342544).

21878304768 is an abundant number, since it is smaller than the sum of its proper divisors (47738380320).

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

21878304768 is an frugal number, since it uses more digits than its factorization.

21878304768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 490 (or 453 counting only the distinct ones).

The product of its (nonzero) digits is 3612672, while the sum is 54.

The spelling of 21878304768 in words is "twenty-one billion, eight hundred seventy-eight million, three hundred four thousand, seven hundred sixty-eight".