1255557565 has 4 divisors (see below), whose sum is σ = 1506669084. Its totient is φ = 1004446048.

The previous prime is 1255557553. The next prime is 1255557599. The reversal of 1255557565 is 5657555521.

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 626450841 + 629106724 = 25029^2 + 25082^2 .

It is a cyclic number.

It is not a de Polignac number, because 1255557565 - 2⁵ = 1255557533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 125555752 + ... + 125555761.

It is an arithmetic number, because the mean of its divisors is an integer number (376667271).

Almost surely, 2^1255557565 is an apocalyptic number.

It is an amenable number.

1255557565 is a deficient number, since it is larger than the sum of its proper divisors (251111519).

1255557565 is an equidigital number, since it uses as much as digits as its factorization.

1255557565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 251111518.

The product of its digits is 1312500, while the sum is 46.

The square root of 1255557565 is about 35433.8477306657. The cubic root of 1255557565 is about 1078.8114396461.

The spelling of 1255557565 in words is "one billion, two hundred fifty-five million, five hundred fifty-seven thousand, five hundred sixty-five".