856403 has 4 divisors (see below), whose sum is σ = 858528. Its totient is φ = 854280.

The previous prime is 856393. The next prime is 856411. The reversal of 856403 is 304658.

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 856403 - 2⁸ = 856147 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (856483) 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, 251 + ... + 1332.

It is an arithmetic number, because the mean of its divisors is an integer number (214632).

2⁸⁵⁶⁴⁰³ is an apocalyptic number.

856403 is a deficient number, since it is larger than the sum of its proper divisors (2125).

856403 is a wasteful number, since it uses less digits than its factorization.

856403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2124.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 856403 is about 925.4204449870. The cubic root of 856403 is about 94.9640861478.

The spelling of 856403 in words is "eight hundred fifty-six thousand, four hundred three".