1291298817 has 4 divisors (see below), whose sum is σ = 1721731760. Its totient is φ = 860865876.

The previous prime is 1291298809. The next prime is 1291298849. The reversal of 1291298817 is 7188921921.

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.

It is not a de Polignac number, because 1291298817 - 2³ = 1291298809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1291298887) 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, 215216467 + ... + 215216472.

It is an arithmetic number, because the mean of its divisors is an integer number (430432940).

Almost surely, 2^1291298817 is an apocalyptic number.

It is an amenable number.

1291298817 is a deficient number, since it is larger than the sum of its proper divisors (430432943).

1291298817 is an equidigital number, since it uses as much as digits as its factorization.

1291298817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 430432942.

The product of its digits is 145152, while the sum is 48.

The square root of 1291298817 is about 35934.6464710591. The cubic root of 1291298817 is about 1088.9524534418.

The spelling of 1291298817 in words is "one billion, two hundred ninety-one million, two hundred ninety-eight thousand, eight hundred seventeen".