1265256065 has 16 divisors (see below), whose sum is σ = 1529747856. Its totient is φ = 1004601600.

The previous prime is 1265256011. The next prime is 1265256077. The reversal of 1265256065 is 5606525621.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 88491649 + 1176764416 = 9407^2 + 34304^2 .

It is not a de Polignac number, because 1265256065 - 2⁶ = 1265256001 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 589895 + ... + 592035.

It is an arithmetic number, because the mean of its divisors is an integer number (95609241).

Almost surely, 2^1265256065 is an apocalyptic number.

It is an amenable number.

1265256065 is a deficient number, since it is larger than the sum of its proper divisors (264491791).

1265256065 is a wasteful number, since it uses less digits than its factorization.

1265256065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2980.

The product of its (nonzero) digits is 108000, while the sum is 38.

The square root of 1265256065 is about 35570.4380771449. The cubic root of 1265256065 is about 1081.5820620651.

The spelling of 1265256065 in words is "one billion, two hundred sixty-five million, two hundred fifty-six thousand, sixty-five".