598991 has 4 divisors (see below), whose sum is σ = 600552. Its totient is φ = 597432.

The previous prime is 598987. The next prime is 598999. The reversal of 598991 is 199895.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 199895 = 5 ⋅39979.

It is a cyclic number.

It is not a de Polignac number, because 598991 - 2² = 598987 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (598999) 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 in 3 ways as a sum of consecutive naturals, for example, 245 + ... + 1121.

It is an arithmetic number, because the mean of its divisors is an integer number (150138).

2⁵⁹⁸⁹⁹¹ is an apocalyptic number.

598991 is a deficient number, since it is larger than the sum of its proper divisors (1561).

598991 is an equidigital number, since it uses as much as digits as its factorization.

598991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1560.

The product of its digits is 29160, while the sum is 41.

The square root of 598991 is about 773.9450884914. The cubic root of 598991 is about 84.2959609162.

The spelling of 598991 in words is "five hundred ninety-eight thousand, nine hundred ninety-one".