2001999999 has 16 divisors (see below), whose sum is σ = 2851767680. Its totient is φ = 1245546720.

The previous prime is 2001999997. The next prime is 2002000027. The reversal of 2001999999 is 9999991002.

It is not a de Polignac number, because 2001999999 - 2¹ = 2001999997 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a Duffinian number.

2001999999 is a modest number, since divided by 99999 gives 20019 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001999997) 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, 258292 + ... + 265929.

It is an arithmetic number, because the mean of its divisors is an integer number (178235480).

Almost surely, 2^2001999999 is an apocalyptic number.

2001999999 is a deficient number, since it is larger than the sum of its proper divisors (849767681).

2001999999 is a wasteful number, since it uses less digits than its factorization.

2001999999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 524310.

The product of its (nonzero) digits is 1062882, while the sum is 57.

The square root of 2001999999 is about 44743.7146312194. The cubic root of 2001999999 is about 1260.3408834548.

The spelling of 2001999999 in words is "two billion, one million, nine hundred ninety-nine thousand, nine hundred ninety-nine".