13121 has 2 divisors, whose sum is σ = 13122.
Its totient is φ = 13120.
The previous prime is 13109. The next prime is 13127. The reversal of 13121 is 12131.
It is a m-pointer prime, because the next prime (13127) can be obtained adding 13121 to its product of digits (6).
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 9025 + 4096 = 95^2 + 64^2
It is a cyclic number.
It is not a de Polignac number, because 13121 - 210 = 12097 is a prime.
It is a Chen prime.
It is a plaindrome in base 3 and base 9.
It is a junction number, because it is equal to n+sod(n) for n = 13099 and 13108.
It is not a weakly prime, because it can be changed into another prime (13127) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6560 + 6561.
It is an arithmetic number, because the mean of its divisors is an integer number (6561).
213121 is an apocalyptic number.
It is an amenable number.
13121 is a deficient number, since it is larger than the sum of its proper divisors (1).
13121 is an equidigital number, since it uses as much as digits as its factorization.
13121 is an evil number, because the sum of its binary digits is even.
The product of its digits is 6, while the sum is 8.
The square root of 13121 is about 114.5469336124.
The cubic root of 13121 is about 23.5860733691.
Adding to 13121 its reverse (12131), we get a palindrome (25252).
Subtracting from 13121 its reverse (12131), we obtain a triangular number (990 = T44).
The spelling of 13121 in words is "thirteen thousand, one hundred twenty-one".