263121613 has 2 divisors, whose sum is σ = 263121614. Its totient is φ = 263121612.

The previous prime is 263121571. The next prime is 263121619. The reversal of 263121613 is 316121362.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 228523689 + 34597924 = 15117^2 + 5882^2 .

It is a cyclic number.

It is not a de Polignac number, because 263121613 - 2²¹ = 261024461 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (263121619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 131560806 + 131560807.

It is an arithmetic number, because the mean of its divisors is an integer number (131560807).

Almost surely, 2^263121613 is an apocalyptic number.

It is an amenable number.

263121613 is a deficient number, since it is larger than the sum of its proper divisors (1).

263121613 is an equidigital number, since it uses as much as digits as its factorization.

263121613 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1296, while the sum is 25.

The square root of 263121613 is about 16221.0237962960. The cubic root of 263121613 is about 640.7945965508.

Adding to 263121613 its reverse (316121362), we get a palindrome (579242975).

The spelling of 263121613 in words is "two hundred sixty-three million, one hundred twenty-one thousand, six hundred thirteen".