1291331943 has 16 divisors (see below), whose sum is σ = 2087001600. Its totient is φ = 782625240.

The previous prime is 1291331911. The next prime is 1291331953. The reversal of 1291331943 is 3491331921.

1291331943 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1291331943 - 2⁵ = 1291331911 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1291331898 and 1291331907.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291331953) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2173663 + ... + 2174256.

It is an arithmetic number, because the mean of its divisors is an integer number (130437600).

Almost surely, 2^1291331943 is an apocalyptic number.

1291331943 is a deficient number, since it is larger than the sum of its proper divisors (795669657).

1291331943 is a wasteful number, since it uses less digits than its factorization.

1291331943 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4347939 (or 4347933 counting only the distinct ones).

The product of its digits is 17496, while the sum is 36.

The square root of 1291331943 is about 35935.1073881796. The cubic root of 1291331943 is about 1088.9617650822.

The spelling of 1291331943 in words is "one billion, two hundred ninety-one million, three hundred thirty-one thousand, nine hundred forty-three".