266340509 has 2 divisors, whose sum is σ = 266340510. Its totient is φ = 266340508.

The previous prime is 266340407. The next prime is 266340517. The reversal of 266340509 is 905043662.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 214183225 + 52157284 = 14635^2 + 7222^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-266340509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (266340539) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 133170254 + 133170255.

It is an arithmetic number, because the mean of its divisors is an integer number (133170255).

Almost surely, 2^266340509 is an apocalyptic number.

It is an amenable number.

266340509 is a deficient number, since it is larger than the sum of its proper divisors (1).

266340509 is an equidigital number, since it uses as much as digits as its factorization.

266340509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 38880, while the sum is 35.

The square root of 266340509 is about 16319.9420648481. The cubic root of 266340509 is about 643.3970645398.

The spelling of 266340509 in words is "two hundred sixty-six million, three hundred forty thousand, five hundred nine".