1991492304985 has 8 divisors (see below), whose sum is σ = 2414427784776. Its totient is φ = 1576769164800.

The previous prime is 1991492304973. The next prime is 1991492305001. The reversal of 1991492304985 is 5894032941991.

It can be written as a sum of positive squares in 4 ways, for example, as 391780853776 + 1599711451209 = 625924^2 + 1264797^2 .

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

It is not a de Polignac number, because 1991492304985 - 2¹¹ = 1991492302937 is a prime.

It is a Duffinian number.

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 7 ways as a sum of consecutive naturals, for example, 2053084366 + ... + 2053085335.

It is an arithmetic number, because the mean of its divisors is an integer number (301803473097).

Almost surely, 2^{1991492304985} is an apocalyptic number.

It is an amenable number.

1991492304985 is a deficient number, since it is larger than the sum of its proper divisors (422935479791).

1991492304985 is an equidigital number, since it uses as much as digits as its factorization.

1991492304985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4106169803.

The product of its (nonzero) digits is 25194240, while the sum is 64.

The spelling of 1991492304985 in words is "one trillion, nine hundred ninety-one billion, four hundred ninety-two million, three hundred four thousand, nine hundred eighty-five".