21423442320 has 240 divisors, whose sum is σ = 82417046400. Its totient is φ = 4885364736.

The previous prime is 21423442291. The next prime is 21423442321. The reversal of 21423442320 is 2324432412.

21423442320 is a `hidden beast` number, since 2 + 1 + 4 + 234 + 423 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is not an unprimeable number, because it can be changed into a prime (21423442321) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2258227 + ... + 2267693.

It is an arithmetic number, because the mean of its divisors is an integer number (343404360).

Almost surely, 2^21423442320 is an apocalyptic number.

21423442320 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 21423442320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41208523200).

21423442320 is an abundant number, since it is smaller than the sum of its proper divisors (60993604080).

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

21423442320 is a wasteful number, since it uses less digits than its factorization.

21423442320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9942 (or 9933 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 27.

Adding to 21423442320 its reverse (2324432412), we get a palindrome (23747874732).

The spelling of 21423442320 in words is "twenty-one billion, four hundred twenty-three million, four hundred forty-two thousand, three hundred twenty".