855121 has 4 divisors (see below), whose sum is σ = 867952. Its totient is φ = 842292.

The previous prime is 855119. The next prime is 855131. The reversal of 855121 is 121558.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 121558 = 2 ⋅60779.

It is a cyclic number.

It is not a de Polignac number, because 855121 - 2¹ = 855119 is a prime.

It is a Duffinian number.

855121 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 855092 and 855101.

It is not an unprimeable number, because it can be changed into a prime (855131) 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, 6315 + ... + 6448.

It is an arithmetic number, because the mean of its divisors is an integer number (216988).

2⁸⁵⁵¹²¹ is an apocalyptic number.

It is an amenable number.

855121 is a deficient number, since it is larger than the sum of its proper divisors (12831).

855121 is a wasteful number, since it uses less digits than its factorization.

855121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12830.

The product of its digits is 400, while the sum is 22.

The square root of 855121 is about 924.7275274371. The cubic root of 855121 is about 94.9166767087.

Adding to 855121 its reverse (121558), we get a palindrome (976679).

The spelling of 855121 in words is "eight hundred fifty-five thousand, one hundred twenty-one".