997687 has 4 divisors (see below), whose sum is σ = 1032120. Its totient is φ = 963256.

The previous prime is 997681. The next prime is 997693. The reversal of 997687 is 786799.

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 (997681) and next prime (997693).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-997687 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (997681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17173 + ... + 17230.

It is an arithmetic number, because the mean of its divisors is an integer number (258030).

2⁹⁹⁷⁶⁸⁷ is an apocalyptic number.

997687 is a deficient number, since it is larger than the sum of its proper divisors (34433).

997687 is a wasteful number, since it uses less digits than its factorization.

997687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34432.

The product of its digits is 190512, while the sum is 46.

The square root of 997687 is about 998.8428304794. The cubic root of 997687 is about 99.9228404794.

The spelling of 997687 in words is "nine hundred ninety-seven thousand, six hundred eighty-seven".