999958 has 4 divisors (see below), whose sum is σ = 1499940. Its totient is φ = 499978.

The previous prime is 999953. The next prime is 999959. The reversal of 999958 is 859999.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 249988 + ... + 249991.

It is an arithmetic number, because the mean of its divisors is an integer number (374985).

2⁹⁹⁹⁹⁵⁸ is an apocalyptic number.

999958 is a deficient number, since it is larger than the sum of its proper divisors (499982).

999958 is a wasteful number, since it uses less digits than its factorization.

999958 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 499981.

The product of its digits is 262440, while the sum is 49.

The square root of 999958 is about 999.9789997795. The cubic root of 999958 is about 99.9985999804.

The spelling of 999958 in words is "nine hundred ninety-nine thousand, nine hundred fifty-eight".