263687993 has 2 divisors, whose sum is σ = 263687994. Its totient is φ = 263687992.

The previous prime is 263687971. The next prime is 263688053. The reversal of 263687993 is 399786362.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 257377849 + 6310144 = 16043^2 + 2512^2 .

It is a cyclic number.

It is not a de Polignac number, because 263687993 - 2⁸ = 263687737 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (263687903) 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, 131843996 + 131843997.

It is an arithmetic number, because the mean of its divisors is an integer number (131843997).

Almost surely, 2^263687993 is an apocalyptic number.

It is an amenable number.

263687993 is a deficient number, since it is larger than the sum of its proper divisors (1).

263687993 is an equidigital number, since it uses as much as digits as its factorization.

263687993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2939328, while the sum is 53.

The square root of 263687993 is about 16238.4726190612. The cubic root of 263687993 is about 641.2540458791.

The spelling of 263687993 in words is "two hundred sixty-three million, six hundred eighty-seven thousand, nine hundred ninety-three".