266686101821 has 2 divisors, whose sum is σ = 266686101822. Its totient is φ = 266686101820.

The previous prime is 266686101779. The next prime is 266686101967. The reversal of 266686101821 is 128101686662.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 180913264921 + 85772836900 = 425339^2 + 292870^2 .

It is a cyclic number.

It is not a de Polignac number, because 266686101821 - 2²² = 266681907517 is a prime.

It is a super-2 number, since 2×266686101821² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (266686103821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 133343050910 + 133343050911.

It is an arithmetic number, because the mean of its divisors is an integer number (133343050911).

Almost surely, 2^266686101821 is an apocalyptic number.

It is an amenable number.

266686101821 is a deficient number, since it is larger than the sum of its proper divisors (1).

266686101821 is an equidigital number, since it uses as much as digits as its factorization.

266686101821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 331776, while the sum is 47.

The spelling of 266686101821 in words is "two hundred sixty-six billion, six hundred eighty-six million, one hundred one thousand, eight hundred twenty-one".