2100099991 has 16 divisors (see below), whose sum is σ = 2422619136. Its totient is φ = 1802520000.

The previous prime is 2100099979. The next prime is 2100100033. The reversal of 2100099991 is 1999900012.

It is a cyclic number.

It is not a de Polignac number, because 2100099991 - 2⁷ = 2100099863 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2100099901) 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, 61125 + ... + 89086.

It is an arithmetic number, because the mean of its divisors is an integer number (151413696).

Almost surely, 2^2100099991 is an apocalyptic number.

2100099991 is a deficient number, since it is larger than the sum of its proper divisors (322519145).

2100099991 is a wasteful number, since it uses less digits than its factorization.

2100099991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150294.

The product of its (nonzero) digits is 13122, while the sum is 40.

The square root of 2100099991 is about 45826.8479278250. The cubic root of 2100099991 is about 1280.5994894889.

The spelling of 2100099991 in words is "two billion, one hundred million, ninety-nine thousand, nine hundred ninety-one".