1266907945 has 4 divisors (see below), whose sum is σ = 1520289540. Its totient is φ = 1013526352.

The previous prime is 1266907903. The next prime is 1266907951. The reversal of 1266907945 is 5497096621.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5497096621 = 23557 ⋅233353.

It can be written as a sum of positive squares in 2 ways, for example, as 890664336 + 376243609 = 29844^2 + 19397^2 .

It is a cyclic number.

It is not a de Polignac number, because 1266907945 - 2²³ = 1258519337 is a prime.

It is a super-2 number, since 2×1266907945² = 3210111482208246050, which contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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, 126690790 + ... + 126690799.

It is an arithmetic number, because the mean of its divisors is an integer number (380072385).

Almost surely, 2^1266907945 is an apocalyptic number.

It is an amenable number.

1266907945 is a deficient number, since it is larger than the sum of its proper divisors (253381595).

1266907945 is an equidigital number, since it uses as much as digits as its factorization.

1266907945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 253381594.

The product of its (nonzero) digits is 816480, while the sum is 49.

The square root of 1266907945 is about 35593.6503466559. The cubic root of 1266907945 is about 1082.0525509672.

The spelling of 1266907945 in words is "one billion, two hundred sixty-six million, nine hundred seven thousand, nine hundred forty-five".