266905021 has 2 divisors, whose sum is σ = 266905022. Its totient is φ = 266905020.

The previous prime is 266905003. The next prime is 266905031. The reversal of 266905021 is 120509662.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 248535225 + 18369796 = 15765^2 + 4286^2 .

It is a cyclic number.

It is not a de Polignac number, because 266905021 - 2²¹ = 264807869 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (266905031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 133452510 + 133452511.

It is an arithmetic number, because the mean of its divisors is an integer number (133452511).

Almost surely, 2^266905021 is an apocalyptic number.

It is an amenable number.

266905021 is a deficient number, since it is larger than the sum of its proper divisors (1).

266905021 is an equidigital number, since it uses as much as digits as its factorization.

266905021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 266905021 is about 16337.2280696573. The cubic root of 266905021 is about 643.8513064433.

The spelling of 266905021 in words is "two hundred sixty-six million, nine hundred five thousand, twenty-one".