21640065223 has 16 divisors (see below), whose sum is σ = 25818232320. Its totient is φ = 17734296096.

The previous prime is 21640065203. The next prime is 21640065247. The reversal of 21640065223 is 32256004612.

It is not a de Polignac number, because 21640065223 - 2²¹ = 21637968071 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21640065203) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 349233 + ... + 406501.

It is an arithmetic number, because the mean of its divisors is an integer number (1613639520).

Almost surely, 2^21640065223 is an apocalyptic number.

21640065223 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21640065223 is a deficient number, since it is larger than the sum of its proper divisors (4178167097).

21640065223 is a wasteful number, since it uses less digits than its factorization.

21640065223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59646.

The product of its (nonzero) digits is 17280, while the sum is 31.

Adding to 21640065223 its reverse (32256004612), we get a palindrome (53896069835).

The spelling of 21640065223 in words is "twenty-one billion, six hundred forty million, sixty-five thousand, two hundred twenty-three".