21422641968 has 1280 divisors, whose sum is σ = 87994368000. Its totient is φ = 4828336128.

The previous prime is 21422641909. The next prime is 21422641973. The reversal of 21422641968 is 86914622412.

It is a happy number.

21422641968 is a `hidden beast` number, since 2 + 1 + 4 + 226 + 419 + 6 + 8 = 666.

It is a super-2 number, since 2×21422641968² (a number of 21 digits) contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 498200955 + ... + 498200997.

It is an arithmetic number, because the mean of its divisors is an integer number (68745600).

Almost surely, 2^21422641968 is an apocalyptic number.

21422641968 is a gapful number since it is divisible by the number (28) 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 21422641968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43997184000).

21422641968 is an abundant number, since it is smaller than the sum of its proper divisors (66571726032).

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

21422641968 is a wasteful number, since it uses less digits than its factorization.

21422641968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151 (or 139 counting only the distinct ones).

The product of its digits is 331776, while the sum is 45.

The spelling of 21422641968 in words is "twenty-one billion, four hundred twenty-two million, six hundred forty-one thousand, nine hundred sixty-eight".