21383792640 has 960 divisors, whose sum is σ = 91329638400. Its totient is φ = 4682022912.

The previous prime is 21383792627. The next prime is 21383792641. The reversal of 21383792640 is 4629738312.

21383792640 is a `hidden beast` number, since 2 + 1 + 383 + 7 + 9 + 264 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (960).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (21383792641) by changing a digit.

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 79 ways as a sum of consecutive naturals, for example, 168376257 + ... + 168376383.

It is an arithmetic number, because the mean of its divisors is an integer number (95135040).

Almost surely, 2^21383792640 is an apocalyptic number.

21383792640 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 21383792640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45664819200).

21383792640 is an abundant number, since it is smaller than the sum of its proper divisors (69945845760).

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

21383792640 is a wasteful number, since it uses less digits than its factorization.

21383792640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202 (or 173 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 45.

The spelling of 21383792640 in words is "twenty-one billion, three hundred eighty-three million, seven hundred ninety-two thousand, six hundred forty".