997889 has 2 divisors, whose sum is σ = 997890. Its totient is φ = 997888.

The previous prime is 997879. The next prime is 997891. The reversal of 997889 is 988799.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 588289 + 409600 = 767^2 + 640^2 .

It is a cyclic number.

It is not a de Polignac number, because 997889 - 2¹² = 993793 is a prime.

Together with 997891, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (997879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498944 + 498945.

It is an arithmetic number, because the mean of its divisors is an integer number (498945).

2⁹⁹⁷⁸⁸⁹ is an apocalyptic number.

It is an amenable number.

997889 is a deficient number, since it is larger than the sum of its proper divisors (1).

997889 is an equidigital number, since it uses as much as digits as its factorization.

997889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 326592, while the sum is 50.

The square root of 997889 is about 998.9439423711. The cubic root of 997889 is about 99.9295837605.

The spelling of 997889 in words is "nine hundred ninety-seven thousand, eight hundred eighty-nine".