21868019712 has 640 divisors, whose sum is σ = 82215492480. Its totient is φ = 5626920960.

The previous prime is 21868019699. The next prime is 21868019729. The reversal of 21868019712 is 21791086812.

It is a super-2 number, since 2×21868019712² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 204373963 + ... + 204374069.

It is an arithmetic number, because the mean of its divisors is an integer number (128461707).

Almost surely, 2^21868019712 is an apocalyptic number.

21868019712 is a gapful number since it is divisible by the number (22) 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 21868019712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41107746240).

21868019712 is an abundant number, since it is smaller than the sum of its proper divisors (60347472768).

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

21868019712 is an equidigital number, since it uses as much as digits as its factorization.

21868019712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167 (or 130 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 45.

The spelling of 21868019712 in words is "twenty-one billion, eight hundred sixty-eight million, nineteen thousand, seven hundred twelve".