1266906784 has 72 divisors (see below), whose sum is σ = 2952592020. Its totient is φ = 531548160.

The previous prime is 1266906779. The next prime is 1266906787. The reversal of 1266906784 is 4876096621.

It can be written as a sum of positive squares in 2 ways, for example, as 1132995600 + 133911184 = 33660^2 + 11572^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1266906787) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 37752 + ... + 62920.

Almost surely, 2^1266906784 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1266906784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1476296010).

1266906784 is an abundant number, since it is smaller than the sum of its proper divisors (1685685236).

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

1266906784 is a wasteful number, since it uses less digits than its factorization.

1266906784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25214 (or 25195 counting only the distinct ones).

The product of its (nonzero) digits is 870912, while the sum is 49.

The square root of 1266906784 is about 35593.6340375635. The cubic root of 1266906784 is about 1082.0522204346.

The spelling of 1266906784 in words is "one billion, two hundred sixty-six million, nine hundred six thousand, seven hundred eighty-four".