813691 has 4 divisors (see below), whose sum is σ = 815584. Its totient is φ = 811800.

The previous prime is 813677. The next prime is 813697. The reversal of 813691 is 196318.

It is a happy number.

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 813691 - 2¹³ = 805499 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (813697) 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, 46 + ... + 1276.

It is an arithmetic number, because the mean of its divisors is an integer number (203896).

2⁸¹³⁶⁹¹ is an apocalyptic number.

813691 is a deficient number, since it is larger than the sum of its proper divisors (1893).

813691 is a wasteful number, since it uses less digits than its factorization.

813691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1892.

The product of its digits is 1296, while the sum is 28.

The square root of 813691 is about 902.0482248749. The cubic root of 813691 is about 93.3583507200.

The spelling of 813691 in words is "eight hundred thirteen thousand, six hundred ninety-one".