121855 has 4 divisors (see below), whose sum is σ = 146232. Its totient is φ = 97480.

The previous prime is 121853. The next prime is 121867. The reversal of 121855 is 558121.

121855 = 140² + 141² + ... + 145².

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 121855 - 2¹ = 121853 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a plaindrome in base 8.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121853) 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, 12181 + ... + 12190.

It is an arithmetic number, because the mean of its divisors is an integer number (36558).

2¹²¹⁸⁵⁵ is an apocalyptic number.

121855 is a deficient number, since it is larger than the sum of its proper divisors (24377).

121855 is an equidigital number, since it uses as much as digits as its factorization.

121855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24376.

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

The square root of 121855 is about 349.0773553240. The cubic root of 121855 is about 49.5770998606.

Adding to 121855 its reverse (558121), we get a palindrome (679976).

The spelling of 121855 in words is "one hundred twenty-one thousand, eight hundred fifty-five".