266789989 has 2 divisors, whose sum is σ = 266789990. Its totient is φ = 266789988.

The previous prime is 266789981. The next prime is 266790023. The reversal of 266789989 is 989987662.

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., 200448964 + 66341025 = 14158^2 + 8145^2 .

It is a cyclic number.

It is not a de Polignac number, because 266789989 - 2³ = 266789981 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 266789989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (266789981) 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, 133394994 + 133394995.

It is an arithmetic number, because the mean of its divisors is an integer number (133394995).

Almost surely, 2^266789989 is an apocalyptic number.

It is an amenable number.

266789989 is a deficient number, since it is larger than the sum of its proper divisors (1).

266789989 is an equidigital number, since it uses as much as digits as its factorization.

266789989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23514624, while the sum is 64.

The square root of 266789989 is about 16333.7071419810. The cubic root of 266789989 is about 643.7587964488.

The spelling of 266789989 in words is "two hundred sixty-six million, seven hundred eighty-nine thousand, nine hundred eighty-nine".