691311 has 16 divisors (see below), whose sum is σ = 988416. Its totient is φ = 428736.

The previous prime is 691309. The next prime is 691333. The reversal of 691311 is 113196.

It is a happy number.

It is not a de Polignac number, because 691311 - 2¹ = 691309 is a prime.

691311 is a lucky number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 691311.

It is not an unprimeable number, because it can be changed into a prime (691381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2851 + ... + 3083.

It is an arithmetic number, because the mean of its divisors is an integer number (61776).

2⁶⁹¹³¹¹ is an apocalyptic number.

691311 is a deficient number, since it is larger than the sum of its proper divisors (297105).

691311 is a wasteful number, since it uses less digits than its factorization.

691311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 302.

The product of its digits is 162, while the sum is 21.

The square root of 691311 is about 831.4511410781. The cubic root of 691311 is about 88.4214886712.

The spelling of 691311 in words is "six hundred ninety-one thousand, three hundred eleven".