850391 has 4 divisors (see below), whose sum is σ = 900432. Its totient is φ = 800352.

The previous prime is 850387. The next prime is 850393. The reversal of 850391 is 193058.

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 850391 - 2² = 850387 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 850391.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (850393) 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, 24995 + ... + 25028.

It is an arithmetic number, because the mean of its divisors is an integer number (225108).

2⁸⁵⁰³⁹¹ is an apocalyptic number.

850391 is a deficient number, since it is larger than the sum of its proper divisors (50041).

850391 is a wasteful number, since it uses less digits than its factorization.

850391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50040.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 850391 is about 922.1664708717. The cubic root of 850391 is about 94.7413462717.

The spelling of 850391 in words is "eight hundred fifty thousand, three hundred ninety-one".