263139689 has 2 divisors, whose sum is σ = 263139690. Its totient is φ = 263139688.

The previous prime is 263139659. The next prime is 263139691. The reversal of 263139689 is 986931362.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 242736400 + 20403289 = 15580^2 + 4517^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-263139689 is a prime.

Together with 263139691, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (263139629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 131569844 + 131569845.

It is an arithmetic number, because the mean of its divisors is an integer number (131569845).

Almost surely, 2^263139689 is an apocalyptic number.

It is an amenable number.

263139689 is a deficient number, since it is larger than the sum of its proper divisors (1).

263139689 is an equidigital number, since it uses as much as digits as its factorization.

263139689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 419904, while the sum is 47.

The square root of 263139689 is about 16221.5809648752. The cubic root of 263139689 is about 640.8092700419.

The spelling of 263139689 in words is "two hundred sixty-three million, one hundred thirty-nine thousand, six hundred eighty-nine".