263648989 has 2 divisors, whose sum is σ = 263648990. Its totient is φ = 263648988.

The previous prime is 263648981. The next prime is 263648999. The reversal of 263648989 is 989846362.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 226743364 + 36905625 = 15058^2 + 6075^2 .

It is a cyclic number.

It is not a de Polignac number, because 263648989 - 2³ = 263648981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (263648981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 131824494 + 131824495.

It is an arithmetic number, because the mean of its divisors is an integer number (131824495).

Almost surely, 2^263648989 is an apocalyptic number.

It is an amenable number.

263648989 is a deficient number, since it is larger than the sum of its proper divisors (1).

263648989 is an equidigital number, since it uses as much as digits as its factorization.

263648989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4478976, while the sum is 55.

The square root of 263648989 is about 16237.2715996254. The cubic root of 263648989 is about 641.2224268106. Note that the first 3 decimals are identical.

It can be divided in two parts, 26364 and 8989, that added together give a palindrome (35353).

The spelling of 263648989 in words is "two hundred sixty-three million, six hundred forty-eight thousand, nine hundred eighty-nine".