691198 has 4 divisors (see below), whose sum is σ = 1036800. Its totient is φ = 345598.

The previous prime is 691193. The next prime is 691199. The reversal of 691198 is 891196.

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 (691193) by changing a digit.

691198 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 (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 172798 + ... + 172801.

It is an arithmetic number, because the mean of its divisors is an integer number (259200).

2⁶⁹¹¹⁹⁸ is an apocalyptic number.

691198 is a deficient number, since it is larger than the sum of its proper divisors (345602).

691198 is a wasteful number, since it uses less digits than its factorization.

691198 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 345601.

The product of its digits is 3888, while the sum is 34.

The square root of 691198 is about 831.3831848191. The cubic root of 691198 is about 88.4166706888.

It can be divided in two parts, 6 and 91198, that added together give a square (91204 = 302²).

The spelling of 691198 in words is "six hundred ninety-one thousand, one hundred ninety-eight".