16722745661 has 2 divisors, whose sum is σ = 16722745662. Its totient is φ = 16722745660.

The previous prime is 16722745621. The next prime is 16722745667. The reversal of 16722745661 is 16654722761.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10717425625 + 6005320036 = 103525^2 + 77494^2 .

It is an emirp because it is prime and its reverse (16654722761) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16722745661 - 2⁶ = 16722745597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16722745667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8361372830 + 8361372831.

It is an arithmetic number, because the mean of its divisors is an integer number (8361372831).

Almost surely, 2^16722745661 is an apocalyptic number.

It is an amenable number.

16722745661 is a deficient number, since it is larger than the sum of its proper divisors (1).

16722745661 is an equidigital number, since it uses as much as digits as its factorization.

16722745661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 846720, while the sum is 47.

The spelling of 16722745661 in words is "sixteen billion, seven hundred twenty-two million, seven hundred forty-five thousand, six hundred sixty-one".