1191871339 has 4 divisors (see below), whose sum is σ = 1243691856. Its totient is φ = 1140050824.

The previous prime is 1191871337. The next prime is 1191871403. The reversal of 1191871339 is 9331781911.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9331781911 = 42307 ⋅220573.

It is a cyclic number.

It is not a de Polignac number, because 1191871339 - 2¹ = 1191871337 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1191871295 and 1191871304.

It is not an unprimeable number, because it can be changed into a prime (1191871333) 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, 25910224 + ... + 25910269.

It is an arithmetic number, because the mean of its divisors is an integer number (310922964).

Almost surely, 2^1191871339 is an apocalyptic number.

1191871339 is a deficient number, since it is larger than the sum of its proper divisors (51820517).

1191871339 is an equidigital number, since it uses as much as digits as its factorization.

1191871339 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51820516.

The product of its digits is 40824, while the sum is 43.

The square root of 1191871339 is about 34523.4896700783. The cubic root of 1191871339 is about 1060.2536888350.

The spelling of 1191871339 in words is "one billion, one hundred ninety-one million, eight hundred seventy-one thousand, three hundred thirty-nine".