997823 has 4 divisors (see below), whose sum is σ = 1050360. Its totient is φ = 945288.

The previous prime is 997813. The next prime is 997877. The reversal of 997823 is 328799.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 328799 = 277 ⋅1187.

It is not a de Polignac number, because 997823 - 2⁴ = 997807 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (997813) 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, 26240 + ... + 26277.

It is an arithmetic number, because the mean of its divisors is an integer number (262590).

2⁹⁹⁷⁸²³ is an apocalyptic number.

997823 is a deficient number, since it is larger than the sum of its proper divisors (52537).

997823 is a wasteful number, since it uses less digits than its factorization.

997823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52536.

The product of its digits is 27216, while the sum is 38.

The square root of 997823 is about 998.9109069382. The cubic root of 997823 is about 99.9273806103.

It can be divided in two parts, 9978 and 23, that added together give a palindrome (10001).

The spelling of 997823 in words is "nine hundred ninety-seven thousand, eight hundred twenty-three".