1999980009 has 12 divisors (see below), whose sum is σ = 2956043376. Its totient is φ = 1302312312.

The previous prime is 1999980007. The next prime is 1999980131. The reversal of 1999980009 is 9000899991.

It is not a de Polignac number, because 1999980009 - 2¹ = 1999980007 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1999980007) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2583567 + ... + 2584340.

It is an arithmetic number, because the mean of its divisors is an integer number (246336948).

Almost surely, 2^1999980009 is an apocalyptic number.

It is an amenable number.

1999980009 is a deficient number, since it is larger than the sum of its proper divisors (956063367).

1999980009 is a wasteful number, since it uses less digits than its factorization.

1999980009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5167956 (or 5167953 counting only the distinct ones).

The product of its (nonzero) digits is 472392, while the sum is 54.

The square root of 1999980009 is about 44721.1360432626. The cubic root of 1999980009 is about 1259.9168520339.

The spelling of 1999980009 in words is "one billion, nine hundred ninety-nine million, nine hundred eighty thousand, nine".