1990372898209 has 4 divisors (see below), whose sum is σ = 1991133456004. Its totient is φ = 1989612340416.

The previous prime is 1990372898203. The next prime is 1990372898233. The reversal of 1990372898209 is 9028982730991.

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 1541687272609 + 448685625600 = 1241647^2 + 669840^2 .

It is a cyclic number.

It is not a de Polignac number, because 1990372898209 - 2⁹ = 1990372897697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1990372898203) 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 3 ways as a sum of consecutive naturals, for example, 380274972 + ... + 380280205.

It is an arithmetic number, because the mean of its divisors is an integer number (497783364001).

Almost surely, 2^{1990372898209} is an apocalyptic number.

It is an amenable number.

1990372898209 is a deficient number, since it is larger than the sum of its proper divisors (760557795).

1990372898209 is an equidigital number, since it uses as much as digits as its factorization.

1990372898209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 760557794.

The product of its (nonzero) digits is 35271936, while the sum is 67.

The spelling of 1990372898209 in words is "one trillion, nine hundred ninety billion, three hundred seventy-two million, eight hundred ninety-eight thousand, two hundred nine".