16505065321 has 2 divisors, whose sum is σ = 16505065322. Its totient is φ = 16505065320.

The previous prime is 16505065279. The next prime is 16505065337. The reversal of 16505065321 is 12356050561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11108106025 + 5396959296 = 105395^2 + 73464^2 .

It is a cyclic number.

It is not a de Polignac number, because 16505065321 - 2¹⁹ = 16504541033 is a prime.

It is not a weakly prime, because it can be changed into another prime (16505065391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8252532660 + 8252532661.

It is an arithmetic number, because the mean of its divisors is an integer number (8252532661).

Almost surely, 2^16505065321 is an apocalyptic number.

It is an amenable number.

16505065321 is a deficient number, since it is larger than the sum of its proper divisors (1).

16505065321 is an equidigital number, since it uses as much as digits as its factorization.

16505065321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27000, while the sum is 34.

The spelling of 16505065321 in words is "sixteen billion, five hundred five million, sixty-five thousand, three hundred twenty-one".