997891344965 has 4 divisors (see below), whose sum is σ = 1197469613964. Its totient is φ = 798313075968.

The previous prime is 997891344959. The next prime is 997891344971. The reversal of 997891344965 is 569443198799.

997891344965 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is an interprime number because it is at equal distance from previous prime (997891344959) and next prime (997891344971).

It can be written as a sum of positive squares in 2 ways, for example, as 379971150724 + 617920194241 = 616418^2 + 786079^2 .

It is a cyclic number.

It is not a de Polignac number, because 997891344965 - 2¹⁸ = 997891082821 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 997891344892 and 997891344901.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 99789134492 + ... + 99789134501.

It is an arithmetic number, because the mean of its divisors is an integer number (299367403491).

Almost surely, 2^997891344965 is an apocalyptic number.

It is an amenable number.

997891344965 is a deficient number, since it is larger than the sum of its proper divisors (199578268999).

997891344965 is a wasteful number, since it uses less digits than its factorization.

997891344965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199578268998.

The product of its digits is 529079040, while the sum is 74.

The spelling of 997891344965 in words is "nine hundred ninety-seven billion, eight hundred ninety-one million, three hundred forty-four thousand, nine hundred sixty-five".