266691541 has 2 divisors, whose sum is σ = 266691542. Its totient is φ = 266691540.

The previous prime is 266691539. The next prime is 266691577. The reversal of 266691541 is 145196662.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 156000100 + 110691441 = 12490^2 + 10521^2 .

It is a cyclic number.

It is not a de Polignac number, because 266691541 - 2¹ = 266691539 is a prime.

It is a super-2 number, since 2×266691541² = 142248756081909362, which contains 22 as substring.

Together with 266691539, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 266691494 and 266691503.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (266691041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 133345770 + 133345771.

It is an arithmetic number, because the mean of its divisors is an integer number (133345771).

Almost surely, 2^266691541 is an apocalyptic number.

It is an amenable number.

266691541 is a deficient number, since it is larger than the sum of its proper divisors (1).

266691541 is an equidigital number, since it uses as much as digits as its factorization.

266691541 is an evil number, because the sum of its binary digits is even.

The product of its digits is 77760, while the sum is 40.

The square root of 266691541 is about 16330.6932185991. The cubic root of 266691541 is about 643.6796023688.

The spelling of 266691541 in words is "two hundred sixty-six million, six hundred ninety-one thousand, five hundred forty-one".