1266655566 has 32 divisors (see below), whose sum is σ = 2764958976. Its totient is φ = 383648000.

The previous prime is 1266655561. The next prime is 1266655571. The reversal of 1266655566 is 6655566621.

It is an interprime number because it is at equal distance from previous prime (1266655561) and next prime (1266655571).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1266655561) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 197551 + ... + 203861.

It is an arithmetic number, because the mean of its divisors is an integer number (86404968).

Almost surely, 2^1266655566 is an apocalyptic number.

1266655566 is an abundant number, since it is smaller than the sum of its proper divisors (1498303410).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1266655566 is a wasteful number, since it uses less digits than its factorization.

1266655566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9368.

The product of its digits is 1944000, while the sum is 48.

The square root of 1266655566 is about 35590.1048888592. The cubic root of 1266655566 is about 1081.9806947924.

It can be divided in two parts, 12666555 and 66, that added together give a palindrome (12666621).

The spelling of 1266655566 in words is "one billion, two hundred sixty-six million, six hundred fifty-five thousand, five hundred sixty-six".