691393 has 4 divisors (see below), whose sum is σ = 713728. Its totient is φ = 669060.

The previous prime is 691381. The next prime is 691399. The reversal of 691393 is 393196.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 691393 - 2¹³ = 683201 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 22303 = 691393 / (6 + 9 + 1 + 3 + 9 + 3).

It is the 832-nd Hogben number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (691399) by changing a digit.

It is a nontrivial repunit in base 831.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11121 + ... + 11182.

It is an arithmetic number, because the mean of its divisors is an integer number (178432).

2⁶⁹¹³⁹³ is an apocalyptic number.

It is an amenable number.

691393 is a deficient number, since it is larger than the sum of its proper divisors (22335).

691393 is a wasteful number, since it uses less digits than its factorization.

691393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22334.

The product of its digits is 4374, while the sum is 31.

The square root of 691393 is about 831.5004509921. The cubic root of 691393 is about 88.4249845775.

The spelling of 691393 in words is "six hundred ninety-one thousand, three hundred ninety-three".