918391 has 8 divisors (see below), whose sum is σ = 984960. Its totient is φ = 853248.

The previous prime is 918389. The next prime is 918397. The reversal of 918391 is 193819.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 918391 - 2¹ = 918389 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (918397) 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 7 ways as a sum of consecutive naturals, for example, 1210 + ... + 1816.

It is an arithmetic number, because the mean of its divisors is an integer number (123120).

2⁹¹⁸³⁹¹ is an apocalyptic number.

918391 is a deficient number, since it is larger than the sum of its proper divisors (66569).

918391 is a wasteful number, since it uses less digits than its factorization.

918391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 713.

The product of its digits is 1944, while the sum is 31.

The square root of 918391 is about 958.3271883861. The cubic root of 918391 is about 97.2021504263.

The spelling of 918391 in words is "nine hundred eighteen thousand, three hundred ninety-one".