1291473891639 has 24 divisors (see below), whose sum is σ = 1947537118800. Its totient is φ = 855204163776.

The previous prime is 1291473891637. The next prime is 1291473891679. The reversal of 1291473891639 is 9361983741921.

1291473891639 is a `hidden beast` number, since 1 + 2 + 91 + 4 + 7 + 389 + 163 + 9 = 666.

It is not a de Polignac number, because 1291473891639 - 2¹ = 1291473891637 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291473891637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17798382 + ... + 17870795.

It is an arithmetic number, because the mean of its divisors is an integer number (81147379950).

Almost surely, 2^{1291473891639} is an apocalyptic number.

1291473891639 is a deficient number, since it is larger than the sum of its proper divisors (656063227161).

1291473891639 is an equidigital number, since it uses as much as digits as its factorization.

1291473891639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35669341 (or 35669329 counting only the distinct ones).

The product of its digits is 17635968, while the sum is 63.

The spelling of 1291473891639 in words is "one trillion, two hundred ninety-one billion, four hundred seventy-three million, eight hundred ninety-one thousand, six hundred thirty-nine".