691243 has 6 divisors (see below), whose sum is σ = 804156. Its totient is φ = 592452.

The previous prime is 691241. The next prime is 691267. The reversal of 691243 is 342196.

It is not a de Polignac number, because 691243 - 2¹ = 691241 is a prime.

It is a Duffinian number.

691243 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (691241) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7005 + ... + 7102.

It is an arithmetic number, because the mean of its divisors is an integer number (134026).

2⁶⁹¹²⁴³ is an apocalyptic number.

691243 is a deficient number, since it is larger than the sum of its proper divisors (112913).

691243 is a wasteful number, since it uses less digits than its factorization.

691243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14121 (or 14114 counting only the distinct ones).

The product of its digits is 1296, while the sum is 25.

The square root of 691243 is about 831.4102477117. The cubic root of 691243 is about 88.4185894172.

The spelling of 691243 in words is "six hundred ninety-one thousand, two hundred forty-three".