858491 has 4 divisors (see below), whose sum is σ = 861000. Its totient is φ = 855984.

The previous prime is 858479. The next prime is 858497. The reversal of 858491 is 194858.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 194858 = 2 ⋅97429.

It is a cyclic number.

It is not a de Polignac number, because 858491 - 2⁶ = 858427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (858497) 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, 641 + ... + 1458.

It is an arithmetic number, because the mean of its divisors is an integer number (215250).

2⁸⁵⁸⁴⁹¹ is an apocalyptic number.

858491 is a deficient number, since it is larger than the sum of its proper divisors (2509).

858491 is a wasteful number, since it uses less digits than its factorization.

858491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2508.

The product of its digits is 11520, while the sum is 35.

The square root of 858491 is about 926.5478940670. The cubic root of 858491 is about 95.0412009654.

The spelling of 858491 in words is "eight hundred fifty-eight thousand, four hundred ninety-one".