19992009 has 8 divisors (see below), whose sum is σ = 28059040. Its totient is φ = 12626496.

The previous prime is 19992001. The next prime is 19992029. The reversal of 19992009 is 90029991.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 19992009 - 2³ = 19992001 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (19992001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 175312 + ... + 175425.

It is an arithmetic number, because the mean of its divisors is an integer number (3507380).

Almost surely, 2^19992009 is an apocalyptic number.

19992009 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

19992009 is a deficient number, since it is larger than the sum of its proper divisors (8067031).

19992009 is a wasteful number, since it uses less digits than its factorization.

19992009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 350759.

The product of its (nonzero) digits is 13122, while the sum is 39.

The square root of 19992009 is about 4471.2424447798. The cubic root of 19992009 is about 271.4056053250.

The spelling of 19992009 in words is "nineteen million, nine hundred ninety-two thousand, nine".