263478989 has 2 divisors, whose sum is σ = 263478990. Its totient is φ = 263478988.

The previous prime is 263478959. The next prime is 263479009. The reversal of 263478989 is 989874362.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 178008964 + 85470025 = 13342^2 + 9245^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-263478989 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (263478959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 131739494 + 131739495.

It is an arithmetic number, because the mean of its divisors is an integer number (131739495).

Almost surely, 2^263478989 is an apocalyptic number.

It is an amenable number.

263478989 is a deficient number, since it is larger than the sum of its proper divisors (1).

263478989 is an equidigital number, since it uses as much as digits as its factorization.

263478989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5225472, while the sum is 56.

The square root of 263478989 is about 16232.0358858647. The cubic root of 263478989 is about 641.0845778083.

The spelling of 263478989 in words is "two hundred sixty-three million, four hundred seventy-eight thousand, nine hundred eighty-nine".