225121 has 4 divisors (see below), whose sum is σ = 242452. Its totient is φ = 207792.
The previous prime is 225119. The next prime is 225133. The reversal of 225121 is 121522.
It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 121522 = 2 ⋅60761.
It can be written as a sum of positive squares in 2 ways, for example, as 112225 + 112896 = 335^2 + 336^2 .
It is not a de Polignac number, because 225121 - 21 = 225119 is a prime.
It is a Harshad number since it is a multiple of its sum of digits (13), and also a Moran number because the ratio is a prime number: 17317 = 225121 / (2 + 2 + 5 + 1 + 2 + 1).
It is a Duffinian number.
225121 is a lucky number.
It is not an unprimeable number, because it can be changed into a prime (225161) 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 3 ways as a sum of consecutive naturals, for example, 8646 + ... + 8671.
It is an arithmetic number, because the mean of its divisors is an integer number (60613).
2225121 is an apocalyptic number.
225121 is the 336-th centered square number.
It is an amenable number.
225121 is a deficient number, since it is larger than the sum of its proper divisors (17331).
225121 is a wasteful number, since it uses less digits than its factorization.
225121 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 17330.
The product of its digits is 40, while the sum is 13.
The square root of 225121 is about 474.4691770811. The cubic root of 225121 is about 60.8329209121.
Adding to 225121 its reverse (121522), we get a palindrome (346643).
It can be divided in two parts, 225 and 121, that multiplied together give a square (27225 = 1652).
The spelling of 225121 in words is "two hundred twenty-five thousand, one hundred twenty-one".
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