1491161391289 has 4 divisors (see below), whose sum is σ = 1492168253940. Its totient is φ = 1490154528640.

The previous prime is 1491161391281. The next prime is 1491161391299. The reversal of 1491161391289 is 9821931611941.

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 949634658064 + 541526733225 = 974492^2 + 735885^2 .

It is a cyclic number.

It is not a de Polignac number, because 1491161391289 - 2³ = 1491161391281 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1491161391281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 503429104 + ... + 503432065.

It is an arithmetic number, because the mean of its divisors is an integer number (373042063485).

Almost surely, 2^{1491161391289} is an apocalyptic number.

It is an amenable number.

1491161391289 is a deficient number, since it is larger than the sum of its proper divisors (1006862651).

1491161391289 is a wasteful number, since it uses less digits than its factorization.

1491161391289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1006862650.

The product of its digits is 839808, while the sum is 55.

The spelling of 1491161391289 in words is "one trillion, four hundred ninety-one billion, one hundred sixty-one million, three hundred ninety-one thousand, two hundred eighty-nine".