1265565649 has 8 divisors (see below), whose sum is σ = 1301481000. Its totient is φ = 1229740416.

The previous prime is 1265565611. The next prime is 1265565659. The reversal of 1265565649 is 9465655621.

It can be written as a sum of positive squares in 4 ways, for example, as 483025 + 1265082624 = 695^2 + 35568^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1265565649 - 2¹¹ = 1265563601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1265565659) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6477 + ... + 50725.

It is an arithmetic number, because the mean of its divisors is an integer number (162685125).

Almost surely, 2^1265565649 is an apocalyptic number.

It is an amenable number.

1265565649 is a deficient number, since it is larger than the sum of its proper divisors (35915351).

1265565649 is an equidigital number, since it uses as much as digits as its factorization.

1265565649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45059.

The product of its digits is 1944000, while the sum is 49.

The square root of 1265565649 is about 35574.7895144862. The cubic root of 1265565649 is about 1081.6702690308.

The spelling of 1265565649 in words is "one billion, two hundred sixty-five million, five hundred sixty-five thousand, six hundred forty-nine".