1266646663 has 4 divisors (see below), whose sum is σ = 1293596640. Its totient is φ = 1239696688.

The previous prime is 1266646631. The next prime is 1266646669. The reversal of 1266646663 is 3666466621.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1266646663 - 2⁵ = 1266646631 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1266646669) 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, 13474918 + ... + 13475011.

It is an arithmetic number, because the mean of its divisors is an integer number (323399160).

Almost surely, 2^1266646663 is an apocalyptic number.

1266646663 is a deficient number, since it is larger than the sum of its proper divisors (26949977).

1266646663 is an equidigital number, since it uses as much as digits as its factorization.

1266646663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26949976.

The product of its digits is 1119744, while the sum is 46.

The square root of 1266646663 is about 35589.9798117391. The cubic root of 1266646663 is about 1081.9781597973.

The spelling of 1266646663 in words is "one billion, two hundred sixty-six million, six hundred forty-six thousand, six hundred sixty-three".