845391 has 4 divisors (see below), whose sum is σ = 1127192. Its totient is φ = 563592.

The previous prime is 845387. The next prime is 845431. The reversal of 845391 is 193548.

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

It is not a de Polignac number, because 845391 - 2² = 845387 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 845391.

It is not an unprimeable number, because it can be changed into a prime (845371) 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, 140896 + ... + 140901.

It is an arithmetic number, because the mean of its divisors is an integer number (281798).

2⁸⁴⁵³⁹¹ is an apocalyptic number.

845391 is a deficient number, since it is larger than the sum of its proper divisors (281801).

845391 is a wasteful number, since it uses less digits than its factorization.

845391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281800.

The product of its digits is 4320, while the sum is 30.

The square root of 845391 is about 919.4514669084. The cubic root of 845391 is about 94.5552992315. Note that the first 3 decimals are identical.

The spelling of 845391 in words is "eight hundred forty-five thousand, three hundred ninety-one".