21368807064 has 384 divisors, whose sum is σ = 71772480000. Its totient is φ = 5662863360.

The previous prime is 21368807063. The next prime is 21368807111. The reversal of 21368807064 is 46070886312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21368807063) by changing a digit.

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 95 ways as a sum of consecutive naturals, for example, 10035952 + ... + 10038080.

It is an arithmetic number, because the mean of its divisors is an integer number (186907500).

Almost surely, 2^21368807064 is an apocalyptic number.

21368807064 is a gapful number since it is divisible by the number (24) 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 21368807064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35886240000).

21368807064 is an abundant number, since it is smaller than the sum of its proper divisors (50403672936).

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

21368807064 is a wasteful number, since it uses less digits than its factorization.

21368807064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2223 (or 2216 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 45.

The spelling of 21368807064 in words is "twenty-one billion, three hundred sixty-eight million, eight hundred seven thousand, sixty-four".