2101999999 has 4 divisors (see below), whose sum is σ = 2293090920. Its totient is φ = 1910909080.

The previous prime is 2101999993. The next prime is 2102000009. The reversal of 2101999999 is 9999991012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2101999999 - 2⁵ = 2101999967 is a prime.

It is a Duffinian number.

2101999999 is a modest number, since divided by 99999 gives 21019 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2101999993) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 95545444 + ... + 95545465.

It is an arithmetic number, because the mean of its divisors is an integer number (573272730).

Almost surely, 2^2101999999 is an apocalyptic number.

2101999999 is a deficient number, since it is larger than the sum of its proper divisors (191090921).

2101999999 is a wasteful number, since it uses less digits than its factorization.

2101999999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191090920.

The product of its (nonzero) digits is 1062882, while the sum is 58.

The square root of 2101999999 is about 45847.5735344849. The cubic root of 2101999999 is about 1280.9855688627.

The spelling of 2101999999 in words is "two billion, one hundred one million, nine hundred ninety-nine thousand, nine hundred ninety-nine".