105998 has 4 divisors (see below), whose sum is σ = 159000. Its totient is φ = 52998.

The previous prime is 105997. The next prime is 106013. The reversal of 105998 is 899501.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 899501 = 881 ⋅1021.

It is a super-2 number, since 2×105998² = 22471152008, which contains 22 as substring.

It is an Ulam number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (105997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 26498 + ... + 26501.

It is an arithmetic number, because the mean of its divisors is an integer number (39750).

2¹⁰⁵⁹⁹⁸ is an apocalyptic number.

105998 is a deficient number, since it is larger than the sum of its proper divisors (53002).

105998 is an equidigital number, since it uses as much as digits as its factorization.

105998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53001.

The product of its (nonzero) digits is 3240, while the sum is 32.

The square root of 105998 is about 325.5733404319. The cubic root of 105998 is about 47.3259372605.

Adding to 105998 its sum of digits (32), we get a triangular number (106030 = T₄₆₀).

The spelling of 105998 in words is "one hundred five thousand, nine hundred ninety-eight".