155121 has 8 divisors (see below), whose sum is σ = 214080. Its totient is φ = 99792.

The previous prime is 155119. The next prime is 155137. The reversal of 155121 is 121551.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 155121 - 2¹ = 155119 is a prime.

It is an Ulam number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 155121.

It is not an unprimeable number, because it can be changed into a prime (155161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 805 + ... + 978.

It is an arithmetic number, because the mean of its divisors is an integer number (26760).

2¹⁵⁵¹²¹ is an apocalyptic number.

It is an amenable number.

155121 is a deficient number, since it is larger than the sum of its proper divisors (58959).

155121 is a wasteful number, since it uses less digits than its factorization.

155121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1815.

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

The square root of 155121 is about 393.8540338755. The cubic root of 155121 is about 53.7308278477.

Adding to 155121 its reverse (121551), we get a palindrome (276672).

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

The spelling of 155121 in words is "one hundred fifty-five thousand, one hundred twenty-one".