263561993 has 2 divisors, whose sum is σ = 263561994. Its totient is φ = 263561992.

The previous prime is 263561959. The next prime is 263562017. The reversal of 263561993 is 399165362.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 161086864 + 102475129 = 12692^2 + 10123^2 .

It is a cyclic number.

It is not a de Polignac number, because 263561993 - 2⁸ = 263561737 is a prime.

It is not a weakly prime, because it can be changed into another prime (263561923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 131780996 + 131780997.

It is an arithmetic number, because the mean of its divisors is an integer number (131780997).

Almost surely, 2^263561993 is an apocalyptic number.

It is an amenable number.

263561993 is a deficient number, since it is larger than the sum of its proper divisors (1).

263561993 is an equidigital number, since it uses as much as digits as its factorization.

263561993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 262440, while the sum is 44.

The square root of 263561993 is about 16234.5924802565. The cubic root of 263561993 is about 641.1518912054.

The spelling of 263561993 in words is "two hundred sixty-three million, five hundred sixty-one thousand, nine hundred ninety-three".