1291289162789 has 4 divisors (see below), whose sum is σ = 1322784020460. Its totient is φ = 1259794305120.

The previous prime is 1291289162749. The next prime is 1291289162851. The reversal of 1291289162789 is 9872619821921.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 563437890625 + 727851272164 = 750625^2 + 853142^2 .

It is a cyclic number.

It is not a de Polignac number, because 1291289162789 - 2³⁶ = 1222569686053 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291289162719) 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, 15747428774 + ... + 15747428855.

It is an arithmetic number, because the mean of its divisors is an integer number (330696005115).

Almost surely, 2^{1291289162789} is an apocalyptic number.

It is an amenable number.

1291289162789 is a deficient number, since it is larger than the sum of its proper divisors (31494857671).

1291289162789 is an equidigital number, since it uses as much as digits as its factorization.

1291289162789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31494857670.

The product of its digits is 15676416, while the sum is 65.

The spelling of 1291289162789 in words is "one trillion, two hundred ninety-one billion, two hundred eighty-nine million, one hundred sixty-two thousand, seven hundred eighty-nine".