1261438807 has 4 divisors (see below), whose sum is σ = 1261741320. Its totient is φ = 1261136296.

The previous prime is 1261438751. The next prime is 1261438819. The reversal of 1261438807 is 7088341621.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1261438807 - 2⁷ = 1261438679 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 1261438807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261438877) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 144913 + ... + 153370.

It is an arithmetic number, because the mean of its divisors is an integer number (315435330).

Almost surely, 2^1261438807 is an apocalyptic number.

1261438807 is a deficient number, since it is larger than the sum of its proper divisors (302513).

1261438807 is an equidigital number, since it uses as much as digits as its factorization.

1261438807 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 302512.

The product of its (nonzero) digits is 64512, while the sum is 40.

The square root of 1261438807 is about 35516.7398137836. The cubic root of 1261438807 is about 1080.4932609075.

The spelling of 1261438807 in words is "one billion, two hundred sixty-one million, four hundred thirty-eight thousand, eight hundred seven".