266278417 has 2 divisors, whose sum is σ = 266278418. Its totient is φ = 266278416.

The previous prime is 266278409. The next prime is 266278423. The reversal of 266278417 is 714872662.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 249924481 + 16353936 = 15809^2 + 4044^2 .

It is a cyclic number.

It is not a de Polignac number, because 266278417 - 2³ = 266278409 is a prime.

It is not a weakly prime, because it can be changed into another prime (266278447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 133139208 + 133139209.

It is an arithmetic number, because the mean of its divisors is an integer number (133139209).

Almost surely, 2^266278417 is an apocalyptic number.

It is an amenable number.

266278417 is a deficient number, since it is larger than the sum of its proper divisors (1).

266278417 is an equidigital number, since it uses as much as digits as its factorization.

266278417 is an evil number, because the sum of its binary digits is even.

The product of its digits is 225792, while the sum is 43.

The square root of 266278417 is about 16318.0396187777. The cubic root of 266278417 is about 643.3470622382.

The spelling of 266278417 in words is "two hundred sixty-six million, two hundred seventy-eight thousand, four hundred seventeen".