266421247 has 2 divisors, whose sum is σ = 266421248. Its totient is φ = 266421246.

The previous prime is 266421241. The next prime is 266421251. The reversal of 266421247 is 742124662.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 266421247 - 2¹¹ = 266419199 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (266421241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 133210623 + 133210624.

It is an arithmetic number, because the mean of its divisors is an integer number (133210624).

Almost surely, 2^266421247 is an apocalyptic number.

266421247 is a deficient number, since it is larger than the sum of its proper divisors (1).

266421247 is an equidigital number, since it uses as much as digits as its factorization.

266421247 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32256, while the sum is 34.

The square root of 266421247 is about 16322.4154768833. The cubic root of 266421247 is about 643.4620707284.

It can be divided in two parts, 26642 and 1247, that added together give a square (27889 = 167²).

The spelling of 266421247 in words is "two hundred sixty-six million, four hundred twenty-one thousand, two hundred forty-seven".