21878984096640 has 512 divisors, whose sum is σ = 84558674995200. Its totient is φ = 5302350028800.

The previous prime is 21878984096633. The next prime is 21878984096707. The reversal of 21878984096640 is 4669048987812.

21878984096640 is a `hidden beast` number, since 2 + 1 + 8 + 78 + 98 + 409 + 6 + 64 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 680660409 + ... + 680692551.

It is an arithmetic number, because the mean of its divisors is an integer number (165153662100).

Almost surely, 2^{21878984096640} is an apocalyptic number.

21878984096640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21878984096640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42279337497600).

21878984096640 is an abundant number, since it is smaller than the sum of its proper divisors (62679690898560).

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

21878984096640 is a wasteful number, since it uses less digits than its factorization.

21878984096640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35763 (or 35745 counting only the distinct ones).

The product of its (nonzero) digits is 334430208, while the sum is 72.

The spelling of 21878984096640 in words is "twenty-one trillion, eight hundred seventy-eight billion, nine hundred eighty-four million, ninety-six thousand, six hundred forty".