1265510013 has 4 divisors (see below), whose sum is σ = 1687346688. Its totient is φ = 843673340.

The previous prime is 1265509997. The next prime is 1265510017. The reversal of 1265510013 is 3100155621.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 3100155621 = 3 ⋅1033385207.

It is a cyclic number.

It is not a de Polignac number, because 1265510013 - 2⁴ = 1265509997 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1265510017) 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, 210918333 + ... + 210918338.

It is an arithmetic number, because the mean of its divisors is an integer number (421836672).

Almost surely, 2^1265510013 is an apocalyptic number.

It is an amenable number.

1265510013 is a deficient number, since it is larger than the sum of its proper divisors (421836675).

1265510013 is an equidigital number, since it uses as much as digits as its factorization.

1265510013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 421836674.

The product of its (nonzero) digits is 900, while the sum is 24.

The square root of 1265510013 is about 35574.0075476464. The cubic root of 1265510013 is about 1081.6544182295.

Adding to 1265510013 its reverse (3100155621), we get a palindrome (4365665634).

The spelling of 1265510013 in words is "one billion, two hundred sixty-five million, five hundred ten thousand, thirteen".