266781961097 has 2 divisors, whose sum is σ = 266781961098. Its totient is φ = 266781961096.

The previous prime is 266781961087. The next prime is 266781961109. The reversal of 266781961097 is 790169187662.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 182042168896 + 84739792201 = 426664^2 + 291101^2 .

It is a cyclic number.

It is not a de Polignac number, because 266781961097 - 2¹⁰ = 266781960073 is a prime.

It is a super-2 number, since 2×266781961097² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (266781961007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 133390980548 + 133390980549.

It is an arithmetic number, because the mean of its divisors is an integer number (133390980549).

Almost surely, 2^266781961097 is an apocalyptic number.

It is an amenable number.

266781961097 is a deficient number, since it is larger than the sum of its proper divisors (1).

266781961097 is an equidigital number, since it uses as much as digits as its factorization.

266781961097 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13716864, while the sum is 62.

The spelling of 266781961097 in words is "two hundred sixty-six billion, seven hundred eighty-one million, nine hundred sixty-one thousand, ninety-seven".