1266815879 has 16 divisors (see below), whose sum is σ = 1489832256. Its totient is φ = 1054425600.

The previous prime is 1266815813. The next prime is 1266815881. The reversal of 1266815879 is 9785186621.

It is a cyclic number.

It is not a de Polignac number, because 1266815879 - 2⁸ = 1266815623 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1266815879.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1266811879) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 135599 + ... + 144639.

It is an arithmetic number, because the mean of its divisors is an integer number (93114516).

Almost surely, 2^1266815879 is an apocalyptic number.

1266815879 is a deficient number, since it is larger than the sum of its proper divisors (223016377).

1266815879 is an equidigital number, since it uses as much as digits as its factorization.

1266815879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9626.

The product of its digits is 1451520, while the sum is 53.

The square root of 1266815879 is about 35592.3570306885. The cubic root of 1266815879 is about 1082.0263394697.

The spelling of 1266815879 in words is "one billion, two hundred sixty-six million, eight hundred fifteen thousand, eight hundred seventy-nine".