21334251680 has 192 divisors, whose sum is σ = 60322848768. Its totient is φ = 6971458560.

The previous prime is 21334251661. The next prime is 21334251709. The reversal of 21334251680 is 8615243312.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 21334251680.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8010029 + ... + 8012691.

It is an arithmetic number, because the mean of its divisors is an integer number (314181504).

Almost surely, 2^21334251680 is an apocalyptic number.

21334251680 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 21334251680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30161424384).

21334251680 is an abundant number, since it is smaller than the sum of its proper divisors (38988597088).

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

21334251680 is a wasteful number, since it uses less digits than its factorization.

21334251680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3019 (or 3011 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 35.

Adding to 21334251680 its reverse (8615243312), we get a palindrome (29949494992).

The spelling of 21334251680 in words is "twenty-one billion, three hundred thirty-four million, two hundred fifty-one thousand, six hundred eighty".