21783424320 has 504 divisors, whose sum is σ = 87786021024. Its totient is φ = 4943296512.

The previous prime is 21783424307. The next prime is 21783424321. The reversal of 21783424320 is 2342438712.

It is a happy number.

21783424320 is a `hidden beast` number, since 217 + 8 + 3 + 4 + 2 + 432 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (504).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21783424321) 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 71 ways as a sum of consecutive naturals, for example, 23002087 + ... + 23003033.

Almost surely, 2^21783424320 is an apocalyptic number.

21783424320 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 21783424320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43893010512).

21783424320 is an abundant number, since it is smaller than the sum of its proper divisors (66002596704).

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

21783424320 is a wasteful number, since it uses less digits than its factorization.

21783424320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1147 (or 1127 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 36.

The spelling of 21783424320 in words is "twenty-one billion, seven hundred eighty-three million, four hundred twenty-four thousand, three hundred twenty".