691423 has 4 divisors (see below), whose sum is σ = 693160. Its totient is φ = 689688.

The previous prime is 691409. The next prime is 691433. The reversal of 691423 is 324196.

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 691423 - 2¹³ = 683231 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691433) 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, 61 + ... + 1177.

It is an arithmetic number, because the mean of its divisors is an integer number (173290).

2⁶⁹¹⁴²³ is an apocalyptic number.

691423 is a deficient number, since it is larger than the sum of its proper divisors (1737).

691423 is a wasteful number, since it uses less digits than its factorization.

691423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1736.

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

The square root of 691423 is about 831.5184904739. The cubic root of 691423 is about 88.4262634985.

The spelling of 691423 in words is "six hundred ninety-one thousand, four hundred twenty-three".