997839 has 20 divisors (see below), whose sum is σ = 1517824. Its totient is φ = 653184.

The previous prime is 997813. The next prime is 997877. The reversal of 997839 is 938799.

It is a happy number.

997839 is nontrivially palindromic in base 2.

It is not a de Polignac number, because 997839 - 2⁵ = 997807 is a prime.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 997794 and 997803.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 997839.

It is not an unprimeable number, because it can be changed into a prime (997879) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 7794 + ... + 7920.

2⁹⁹⁷⁸³⁹ is an apocalyptic number.

997839 is a deficient number, since it is larger than the sum of its proper divisors (519985).

997839 is a wasteful number, since it uses less digits than its factorization.

997839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236 (or 227 counting only the distinct ones).

The product of its digits is 122472, while the sum is 45.

The square root of 997839 is about 998.9189156283. The cubic root of 997839 is about 99.9279147163.

The spelling of 997839 in words is "nine hundred ninety-seven thousand, eight hundred thirty-nine".