1261326647 has 16 divisors (see below), whose sum is σ = 1583362560. Its totient is φ = 979700832.

The previous prime is 1261326643. The next prime is 1261326673. The reversal of 1261326647 is 7466231621.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1261326647 - 2² = 1261326643 is a prime.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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 1261326647.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261326641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 203108 + ... + 209225.

It is an arithmetic number, because the mean of its divisors is an integer number (98960160).

Almost surely, 2^1261326647 is an apocalyptic number.

1261326647 is a deficient number, since it is larger than the sum of its proper divisors (322035913).

1261326647 is a wasteful number, since it uses less digits than its factorization.

1261326647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 412382.

The product of its digits is 72576, while the sum is 38.

The square root of 1261326647 is about 35515.1608049295. The cubic root of 1261326647 is about 1080.4612361763.

The spelling of 1261326647 in words is "one billion, two hundred sixty-one million, three hundred twenty-six thousand, six hundred forty-seven".