997971529717 has 4 divisors (see below), whose sum is σ = 997974027180. Its totient is φ = 997969032256.

The previous prime is 997971529699. The next prime is 997971529843. The reversal of 997971529717 is 717925179799.

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 694812270916 + 303159258801 = 833554^2 + 550599^2 .

It is a 3-Lehmer number, since φ(997971529717) divides (997971529717-1)³.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-997971529717 is a prime.

It is a deceptive number, since it divides R_997971529716.

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 997971529717.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (997971524717) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 499492 + ... + 1498477.

It is an arithmetic number, because the mean of its divisors is an integer number (249493506795).

Almost surely, 2^997971529717 is an apocalyptic number.

997971529717 is the 499493-rd decagonal number.

It is an amenable number.

997971529717 is a deficient number, since it is larger than the sum of its proper divisors (2497463).

997971529717 is a wasteful number, since it uses less digits than its factorization.

997971529717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2497462.

The product of its digits is 157529610, while the sum is 73.

The spelling of 997971529717 in words is "nine hundred ninety-seven billion, nine hundred seventy-one million, five hundred twenty-nine thousand, seven hundred seventeen".