21713316065 has 16 divisors (see below), whose sum is σ = 29822280192. Its totient is φ = 14867121984.

The previous prime is 21713316029. The next prime is 21713316067. The reversal of 21713316065 is 56061331712.

It is a cyclic number.

It is not a de Polignac number, because 21713316065 - 2⁸ = 21713315809 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21713316067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 434489 + ... + 481878.

It is an arithmetic number, because the mean of its divisors is an integer number (1863892512).

Almost surely, 2^21713316065 is an apocalyptic number.

It is an amenable number.

21713316065 is a deficient number, since it is larger than the sum of its proper divisors (8108964127).

21713316065 is an equidigital number, since it uses as much as digits as its factorization.

21713316065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 917056.

The product of its (nonzero) digits is 22680, while the sum is 35.

Adding to 21713316065 its reverse (56061331712), we get a palindrome (77774647777).

The spelling of 21713316065 in words is "twenty-one billion, seven hundred thirteen million, three hundred sixteen thousand, sixty-five".