856121 has 16 divisors (see below), whose sum is σ = 1061760. Its totient is φ = 673920.

The previous prime is 856117. The next prime is 856133. The reversal of 856121 is 121658.

It is a cyclic number.

It is not a de Polignac number, because 856121 - 2² = 856117 is a prime.

It is an alternating number because its digits alternate between even and odd.

856121 is an undulating number in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (856111) 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, 5375 + ... + 5531.

It is an arithmetic number, because the mean of its divisors is an integer number (66360).

2⁸⁵⁶¹²¹ is an apocalyptic number.

It is an amenable number.

856121 is a deficient number, since it is larger than the sum of its proper divisors (205639).

856121 is a wasteful number, since it uses less digits than its factorization.

856121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224.

The product of its digits is 480, while the sum is 23.

The square root of 856121 is about 925.2680692643. The cubic root of 856121 is about 94.9536616116.

Adding to 856121 its reverse (121658), we get a palindrome (977779).

The spelling of 856121 in words is "eight hundred fifty-six thousand, one hundred twenty-one".