16720540717 has 4 divisors (see below), whose sum is σ = 16789920796. Its totient is φ = 16651160640.

The previous prime is 16720540699. The next prime is 16720540769. The reversal of 16720540717 is 71704502761.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11427396201 + 5293144516 = 106899^2 + 72754^2 .

It is a cyclic number.

It is not a de Polignac number, because 16720540717 - 2⁷ = 16720540589 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16720540717.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16720540787) 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 3 ways as a sum of consecutive naturals, for example, 34689678 + ... + 34690159.

It is an arithmetic number, because the mean of its divisors is an integer number (4197480199).

Almost surely, 2^16720540717 is an apocalyptic number.

It is an amenable number.

16720540717 is a deficient number, since it is larger than the sum of its proper divisors (69380079).

16720540717 is an equidigital number, since it uses as much as digits as its factorization.

16720540717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69380078.

The product of its (nonzero) digits is 82320, while the sum is 40.

The spelling of 16720540717 in words is "sixteen billion, seven hundred twenty million, five hundred forty thousand, seven hundred seventeen".