55121 has 4 divisors (see below), whose sum is σ = 60144. Its totient is φ = 50100.

The previous prime is 55117. The next prime is 55127. The reversal of 55121 is 12155.

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.

It is a cyclic number.

It is not a de Polignac number, because 55121 - 2² = 55117 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 55096 and 55105.

It is not an unprimeable number, because it can be changed into a prime (55127) 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, 2495 + ... + 2516.

It is an arithmetic number, because the mean of its divisors is an integer number (15036).

2⁵⁵¹²¹ is an apocalyptic number.

It is an amenable number.

55121 is a deficient number, since it is larger than the sum of its proper divisors (5023).

55121 is a wasteful number, since it uses less digits than its factorization.

55121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5022.

The product of its digits is 50, while the sum is 14.

The square root of 55121 is about 234.7786191287. The cubic root of 55121 is about 38.0573924992.

Adding to 55121 its reverse (12155), we get a palindrome (67276).

The spelling of 55121 in words is "fifty-five thousand, one hundred twenty-one".