263984509 has 2 divisors, whose sum is σ = 263984510. Its totient is φ = 263984508.

The previous prime is 263984447. The next prime is 263984533. The reversal of 263984509 is 905489362.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 168922009 + 95062500 = 12997^2 + 9750^2 .

It is a cyclic number.

It is not a de Polignac number, because 263984509 - 2¹⁹ = 263460221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (263984549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 131992254 + 131992255.

It is an arithmetic number, because the mean of its divisors is an integer number (131992255).

Almost surely, 2^263984509 is an apocalyptic number.

It is an amenable number.

263984509 is a deficient number, since it is larger than the sum of its proper divisors (1).

263984509 is an equidigital number, since it uses as much as digits as its factorization.

263984509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 466560, while the sum is 46.

The square root of 263984509 is about 16247.6000997070. The cubic root of 263984509 is about 641.4943183006.

The spelling of 263984509 in words is "two hundred sixty-three million, nine hundred eighty-four thousand, five hundred nine".