21987384822 has 64 divisors (see below), whose sum is σ = 52791298560. Its totient is φ = 6743246112.

The previous prime is 21987384781. The next prime is 21987384823. The reversal of 21987384822 is 22848378912.

21987384822 is a `hidden beast` number, since 2 + 1 + 98 + 73 + 8 + 482 + 2 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21987384823) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 164503 + ... + 266525.

It is an arithmetic number, because the mean of its divisors is an integer number (824864040).

Almost surely, 2^21987384822 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21987384822, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26395649280).

21987384822 is an abundant number, since it is smaller than the sum of its proper divisors (30803913738).

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

21987384822 is a wasteful number, since it uses less digits than its factorization.

21987384822 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102354 (or 102348 counting only the distinct ones).

The product of its digits is 3096576, while the sum is 54.

The spelling of 21987384822 in words is "twenty-one billion, nine hundred eighty-seven million, three hundred eighty-four thousand, eight hundred twenty-two".