1266809680 has 40 divisors (see below), whose sum is σ = 2958237000. Its totient is φ = 504503808.

The previous prime is 1266809653. The next prime is 1266809681. The reversal of 1266809680 is 869086621.

It can be written as a sum of positive squares in 4 ways, for example, as 301091904 + 965717776 = 17352^2 + 31076^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 1266809680.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1266809681) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16255 + ... + 52894.

It is an arithmetic number, because the mean of its divisors is an integer number (73955925).

Almost surely, 2^1266809680 is an apocalyptic number.

1266809680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1266809680 is an abundant number, since it is smaller than the sum of its proper divisors (1691427320).

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

1266809680 is a wasteful number, since it uses less digits than its factorization.

1266809680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69391 (or 69385 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 46.

The square root of 1266809680 is about 35592.2699472793. The cubic root of 1266809680 is about 1082.0245745481.

The spelling of 1266809680 in words is "one billion, two hundred sixty-six million, eight hundred nine thousand, six hundred eighty".