16720331717 has 2 divisors, whose sum is σ = 16720331718. Its totient is φ = 16720331716.

The previous prime is 16720331713. The next prime is 16720331737. The reversal of 16720331717 is 71713302761.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15408008641 + 1312323076 = 124129^2 + 36226^2 .

It is a cyclic number.

It is not a de Polignac number, because 16720331717 - 2² = 16720331713 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16720331713) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8360165858 + 8360165859.

It is an arithmetic number, because the mean of its divisors is an integer number (8360165859).

Almost surely, 2^16720331717 is an apocalyptic number.

It is an amenable number.

16720331717 is a deficient number, since it is larger than the sum of its proper divisors (1).

16720331717 is an equidigital number, since it uses as much as digits as its factorization.

16720331717 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 37044, while the sum is 38.

The spelling of 16720331717 in words is "sixteen billion, seven hundred twenty million, three hundred thirty-one thousand, seven hundred seventeen".