1261342513 has 4 divisors (see below), whose sum is σ = 1261553728. Its totient is φ = 1261131300.

The previous prime is 1261342487. The next prime is 1261342549. The reversal of 1261342513 is 3152431621.

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: 3152431621 = 491 ⋅6420431.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1261342513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1261342583) 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, 96381 + ... + 108682.

It is an arithmetic number, because the mean of its divisors is an integer number (315388432).

Almost surely, 2^1261342513 is an apocalyptic number.

It is an amenable number.

1261342513 is a deficient number, since it is larger than the sum of its proper divisors (211215).

1261342513 is an equidigital number, since it uses as much as digits as its factorization.

1261342513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211214.

The product of its digits is 4320, while the sum is 28.

The square root of 1261342513 is about 35515.3841736226. The cubic root of 1261342513 is about 1080.4657664662.

The spelling of 1261342513 in words is "one billion, two hundred sixty-one million, three hundred forty-two thousand, five hundred thirteen".