121155 has 16 divisors (see below), whose sum is σ = 199584. Its totient is φ = 62720.

The previous prime is 121151. The next prime is 121157. The reversal of 121155 is 551121.

It is not a de Polignac number, because 121155 - 2² = 121151 is a prime.

It is a super-4 number, since 4×121155⁴ (a number of 21 digits) contains 4444 as substring. Note that it is a super-d number also for d = 3.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is not an unprimeable number, because it can be changed into a prime (121151) 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, 517 + ... + 713.

It is an arithmetic number, because the mean of its divisors is an integer number (12474).

2¹²¹¹⁵⁵ is an apocalyptic number.

121155 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

121155 is a deficient number, since it is larger than the sum of its proper divisors (78429).

121155 is a wasteful number, since it uses less digits than its factorization.

121155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 246.

The product of its digits is 50, while the sum is 15.

The square root of 121155 is about 348.0732681491. The cubic root of 121155 is about 49.4819850780.

Adding to 121155 its reverse (551121), we get a palindrome (672276).

It can be divided in two parts, 121 and 155, that added together give a triangular number (276 = T₂₃).

The spelling of 121155 in words is "one hundred twenty-one thousand, one hundred fifty-five".