856401 has 16 divisors (see below), whose sum is σ = 1405824. Its totient is φ = 451584.

The previous prime is 856393. The next prime is 856411. The reversal of 856401 is 104658.

It is not a de Polignac number, because 856401 - 2³ = 856393 is a prime.

It is not an unprimeable number, because it can be changed into a prime (856411) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1296 + ... + 1841.

It is an arithmetic number, because the mean of its divisors is an integer number (87864).

2⁸⁵⁶⁴⁰¹ is an apocalyptic number.

It is an amenable number.

856401 is a deficient number, since it is larger than the sum of its proper divisors (549423).

856401 is a wasteful number, since it uses less digits than its factorization.

856401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3160.

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 856401 is about 925.4193643965. The cubic root of 856401 is about 94.9640122230.

The spelling of 856401 in words is "eight hundred fifty-six thousand, four hundred one".