1289644121391 has 16 divisors (see below), whose sum is σ = 1810176867840. Its totient is φ = 814444562880.

The previous prime is 1289644121357. The next prime is 1289644121393. The reversal of 1289644121391 is 1931214469821.

It is not a de Polignac number, because 1289644121391 - 2⁷ = 1289644121263 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1289644121393) 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, 239470 + ... + 1623771.

It is an arithmetic number, because the mean of its divisors is an integer number (113136054240).

Almost surely, 2^{1289644121391} is an apocalyptic number.

1289644121391 is a deficient number, since it is larger than the sum of its proper divisors (520532746449).

1289644121391 is a wasteful number, since it uses less digits than its factorization.

1289644121391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1875406.

The product of its digits is 746496, while the sum is 51.

The spelling of 1289644121391 in words is "one trillion, two hundred eighty-nine billion, six hundred forty-four million, one hundred twenty-one thousand, three hundred ninety-one".