21304216365 has 16 divisors (see below), whose sum is σ = 34233046848. Its totient is φ = 11313481856.

The previous prime is 21304216363. The next prime is 21304216429. The reversal of 21304216365 is 56361240312.

It is a cyclic number.

It is not a de Polignac number, because 21304216365 - 2¹ = 21304216363 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21304216363) 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 15 ways as a sum of consecutive naturals, for example, 3044319 + ... + 3051308.

It is an arithmetic number, because the mean of its divisors is an integer number (2139565428).

Almost surely, 2^21304216365 is an apocalyptic number.

It is an amenable number.

21304216365 is a deficient number, since it is larger than the sum of its proper divisors (12928830483).

21304216365 is a wasteful number, since it uses less digits than its factorization.

21304216365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6095868.

The product of its (nonzero) digits is 25920, while the sum is 33.

Adding to 21304216365 its reverse (56361240312), we get a palindrome (77665456677).

The spelling of 21304216365 in words is "twenty-one billion, three hundred four million, two hundred sixteen thousand, three hundred sixty-five".