1991100001101 has 16 divisors (see below), whose sum is σ = 2720322880128. Its totient is φ = 1294656934400.

The previous prime is 1991100001069. The next prime is 1991100001129. The reversal of 1991100001101 is 1011000011991.

It is not a de Polignac number, because 1991100001101 - 2⁵ = 1991100001069 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1991100001151) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1861020 + ... + 2728661.

It is an arithmetic number, because the mean of its divisors is an integer number (170020180008).

Almost surely, 2^{1991100001101} is an apocalyptic number.

It is an amenable number.

1991100001101 is a deficient number, since it is larger than the sum of its proper divisors (729222879027).

1991100001101 is a wasteful number, since it uses less digits than its factorization.

1991100001101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4593252.

The product of its (nonzero) digits is 81, while the sum is 24.

The spelling of 1991100001101 in words is "one trillion, nine hundred ninety-one billion, one hundred million, one thousand, one hundred one".