1291185842 has 8 divisors (see below), whose sum is σ = 1940321136. Its totient is φ = 644412132.

The previous prime is 1291185827. The next prime is 1291185859. The reversal of 1291185842 is 2485811921.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 1291185842.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 589028 + ... + 591215.

It is an arithmetic number, because the mean of its divisors is an integer number (242540142).

Almost surely, 2^1291185842 is an apocalyptic number.

1291185842 is a deficient number, since it is larger than the sum of its proper divisors (649135294).

1291185842 is a wasteful number, since it uses less digits than its factorization.

1291185842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1180792.

The product of its digits is 46080, while the sum is 41.

The square root of 1291185842 is about 35933.0744857715. The cubic root of 1291185842 is about 1088.9206952384.

The spelling of 1291185842 in words is "one billion, two hundred ninety-one million, one hundred eighty-five thousand, eight hundred forty-two".