691351 has 4 divisors (see below), whose sum is σ = 694600. Its totient is φ = 688104.

The previous prime is 691349. The next prime is 691363. The reversal of 691351 is 153196.

691351 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 691351 - 2¹ = 691349 is a prime.

It is a Duffinian number.

691351 is a lucky number.

It is a congruent number.

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

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1281 + ... + 1738.

It is an arithmetic number, because the mean of its divisors is an integer number (173650).

2⁶⁹¹³⁵¹ is an apocalyptic number.

691351 is a deficient number, since it is larger than the sum of its proper divisors (3249).

691351 is a wasteful number, since it uses less digits than its factorization.

691351 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3248.

The product of its digits is 810, while the sum is 25.

The square root of 691351 is about 831.4751950600. The cubic root of 691351 is about 88.4231940258.

The spelling of 691351 in words is "six hundred ninety-one thousand, three hundred fifty-one".