266621616100666 has 8 divisors (see below), whose sum is σ = 400096263742164. Its totient is φ = 133256194853280.

The previous prime is 266621616100661. The next prime is 266621616100787. The reversal of 266621616100666 is 666001616126662.

It can be written as a sum of positive squares in 2 ways, for example, as 262014922265625 + 4606693835041 = 16186875^2 + 2146321^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (266621616100661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27306592425 + ... + 27306602188.

Almost surely, 2^{266621616100666} is an apocalyptic number.

266621616100666 is a deficient number, since it is larger than the sum of its proper divisors (133474647641498).

266621616100666 is a wasteful number, since it uses less digits than its factorization.

266621616100666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54613197056.

The product of its (nonzero) digits is 6718464, while the sum is 55.

The spelling of 266621616100666 in words is "two hundred sixty-six trillion, six hundred twenty-one billion, six hundred sixteen million, one hundred thousand, six hundred sixty-six".