13205531 has 2 divisors, whose sum is σ = 13205532. Its totient is φ = 13205530.

The previous prime is 13205509. The next prime is 13205537. The reversal of 13205531 is 13550231.

It is a strong prime.

It is an emirp because it is prime and its reverse (13550231) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 13205531 - 2¹⁴ = 13189147 is a prime.

It is a super-2 number, since 2×13205531² = 348772097983922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (13205537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6602765 + 6602766.

It is an arithmetic number, because the mean of its divisors is an integer number (6602766).

Almost surely, 2^13205531 is an apocalyptic number.

13205531 is a deficient number, since it is larger than the sum of its proper divisors (1).

13205531 is an equidigital number, since it uses as much as digits as its factorization.

13205531 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 450, while the sum is 20.

The square root of 13205531 is about 3633.9415240204. The cubic root of 13205531 is about 236.3661545410.

Adding to 13205531 its reverse (13550231), we get a palindrome (26755762).

The spelling of 13205531 in words is "thirteen million, two hundred five thousand, five hundred thirty-one".