266291521 has 2 divisors, whose sum is σ = 266291522. Its totient is φ = 266291520.

The previous prime is 266291489. The next prime is 266291527. The reversal of 266291521 is 125192662.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 245360896 + 20930625 = 15664^2 + 4575^2 .

It is a cyclic number.

It is not a de Polignac number, because 266291521 - 2⁵ = 266291489 is a prime.

It is a super-2 number, since 2×266291521² = 141822348312986882, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (266291527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 133145760 + 133145761.

It is an arithmetic number, because the mean of its divisors is an integer number (133145761).

Almost surely, 2^266291521 is an apocalyptic number.

It is an amenable number.

266291521 is a deficient number, since it is larger than the sum of its proper divisors (1).

266291521 is an equidigital number, since it uses as much as digits as its factorization.

266291521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12960, while the sum is 34.

The square root of 266291521 is about 16318.4411326572. The cubic root of 266291521 is about 643.3576154550.

The spelling of 266291521 in words is "two hundred sixty-six million, two hundred ninety-one thousand, five hundred twenty-one".