1266136640 has 28 divisors (see below), whose sum is σ = 3014988636. Its totient is φ = 506454528.

The previous prime is 1266136609. The next prime is 1266136699. The reversal of 1266136640 is 466316621.

It can be written as a sum of positive squares in 2 ways, for example, as 592630336 + 673506304 = 24344^2 + 25952^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1266136640.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1978019 + ... + 1978658.

Almost surely, 2^1266136640 is an apocalyptic number.

1266136640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1266136640 is an abundant number, since it is smaller than the sum of its proper divisors (1748851996).

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

1266136640 is an equidigital number, since it uses as much as digits as its factorization.

1266136640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3956694 (or 3956684 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 35.

The square root of 1266136640 is about 35582.8138291507. The cubic root of 1266136640 is about 1081.8329186010.

The spelling of 1266136640 in words is "one billion, two hundred sixty-six million, one hundred thirty-six thousand, six hundred forty".