1991110002002 has 24 divisors (see below), whose sum is σ = 3285193671900. Its totient is φ = 904407511040.

The previous prime is 1991110001983. The next prime is 1991110002121. The reversal of 1991110002002 is 2002000111991.

It can be written as a sum of positive squares in 2 ways, for example, as 1634329571281 + 356780430721 = 1278409^2 + 597311^2 .

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 2578727 + ... + 3260682.

Almost surely, 2^{1991110002002} is an apocalyptic number.

1991110002002 is a deficient number, since it is larger than the sum of its proper divisors (1294083669898).

1991110002002 is a wasteful number, since it uses less digits than its factorization.

1991110002002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5840842 (or 5840831 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 26.

Adding to 1991110002002 its reverse (2002000111991), we get a palindrome (3993110113993).

The spelling of 1991110002002 in words is "one trillion, nine hundred ninety-one billion, one hundred ten million, two thousand, two".