998779 has 2 divisors, whose sum is σ = 998780. Its totient is φ = 998778.

The previous prime is 998759. The next prime is 998813. The reversal of 998779 is 977899.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 998779 - 2⁷ = 998651 is a prime.

It is not a weakly prime, because it can be changed into another prime (998749) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499389 + 499390.

It is an arithmetic number, because the mean of its divisors is an integer number (499390).

2⁹⁹⁸⁷⁷⁹ is an apocalyptic number.

998779 is a deficient number, since it is larger than the sum of its proper divisors (1).

998779 is an equidigital number, since it uses as much as digits as its factorization.

998779 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 998779 is about 999.3893135310. The cubic root of 998779 is about 99.9592834239.

The spelling of 998779 in words is "nine hundred ninety-eight thousand, seven hundred seventy-nine".