1306642565 has 4 divisors (see below), whose sum is σ = 1567971084. Its totient is φ = 1045314048.

The previous prime is 1306642511. The next prime is 1306642567. The reversal of 1306642565 is 5652466031.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 299913124 + 1006729441 = 17318^2 + 31729^2 .

It is a cyclic number.

It is not a de Polignac number, because 1306642565 - 2¹⁰ = 1306641541 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1306642567) 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, 130664252 + ... + 130664261.

It is an arithmetic number, because the mean of its divisors is an integer number (391992771).

Almost surely, 2^1306642565 is an apocalyptic number.

It is an amenable number.

1306642565 is a deficient number, since it is larger than the sum of its proper divisors (261328519).

1306642565 is an equidigital number, since it uses as much as digits as its factorization.

1306642565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 261328518.

The product of its (nonzero) digits is 129600, while the sum is 38.

The square root of 1306642565 is about 36147.5111868023. The cubic root of 1306642565 is about 1093.2486100714.

The spelling of 1306642565 in words is "one billion, three hundred six million, six hundred forty-two thousand, five hundred sixty-five".