2531 has 2 divisors, whose sum is σ = 2532.
Its totient is φ = 2530.
The previous prime is 2521. The next prime is 2539. The reversal of 2531 is 1352.
2531 = T26 + T27 + ... +
2531 is nontrivially palindromic in base 15.
It is a strong prime.
It is a cyclic number.
It is not a de Polignac number, because 2531 - 26 = 2467 is a prime.
It is a super-2 number, since 2×25312 = 12811922, which contains 22 as substring.
It is a Chen prime.
2531 is an undulating number in base 15.
It is a plaindrome in base 12.
It is a nialpdrome in base 14.
It is not a weakly prime, because it can be changed into another prime (2539) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (7) of ones.
It is a good prime.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1265 + 1266.
It is an arithmetic number, because the mean of its divisors is an integer number (1266).
2531 is the 23-rd centered decagonal number.
2531 is a deficient number, since it is larger than the sum of its proper divisors (1).
2531 is an equidigital number, since it uses as much as digits as its factorization.
2531 is an odious number, because the sum of its binary digits is odd.
The product of its digits is 30, while the sum is 11.
The square root of 2531 is about 50.3090449124.
The cubic root of 2531 is about 13.6279557597.
Adding to 2531 its reverse (1352), we get a palindrome (3883).
The spelling of 2531 in words is "two thousand, five hundred thirty-one".