209158 has 4 divisors (see below), whose sum is σ = 313740. Its totient is φ = 104578.

The previous prime is 209147. The next prime is 209159. The reversal of 209158 is 851902.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209159) by changing a digit.

209158 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 52288 + ... + 52291.

It is an arithmetic number, because the mean of its divisors is an integer number (78435).

2²⁰⁹¹⁵⁸ is an apocalyptic number.

209158 is a deficient number, since it is larger than the sum of its proper divisors (104582).

209158 is a wasteful number, since it uses less digits than its factorization.

209158 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104581.

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 209158 is about 457.3379494422. The cubic root of 209158 is about 59.3596721283.

It can be divided in two parts, 2091 and 58, that multiplied together give a triangular number (121278 = T₄₉₂).

The spelling of 209158 in words is "two hundred nine thousand, one hundred fifty-eight".