978997 has 2 divisors, whose sum is σ = 978998. Its totient is φ = 978996.

The previous prime is 978973. The next prime is 979001. The reversal of 978997 is 799879.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 617796 + 361201 = 786^2 + 601^2 .

It is a cyclic number.

It is not a de Polignac number, because 978997 - 2¹⁹ = 454709 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 978997.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (978907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 489498 + 489499.

It is an arithmetic number, because the mean of its divisors is an integer number (489499).

2⁹⁷⁸⁹⁹⁷ is an apocalyptic number.

It is an amenable number.

978997 is a deficient number, since it is larger than the sum of its proper divisors (1).

978997 is an equidigital number, since it uses as much as digits as its factorization.

978997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 285768, while the sum is 49.

The square root of 978997 is about 989.4427724735. The cubic root of 978997 is about 99.2949405954.

The spelling of 978997 in words is "nine hundred seventy-eight thousand, nine hundred ninety-seven".