16001999 has 8 divisors (see below), whose sum is σ = 17287200. Its totient is φ = 14724576.

The previous prime is 16001969. The next prime is 16002001. The reversal of 16001999 is 99910061.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16001999 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 (16001959) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2774 + ... + 6300.

It is an arithmetic number, because the mean of its divisors is an integer number (2160900).

Almost surely, 2^16001999 is an apocalyptic number.

16001999 is a deficient number, since it is larger than the sum of its proper divisors (1285201).

16001999 is a wasteful number, since it uses less digits than its factorization.

16001999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3889.

The product of its (nonzero) digits is 4374, while the sum is 35.

The square root of 16001999 is about 4000.2498671958. The cubic root of 16001999 is about 251.9947036344.

The spelling of 16001999 in words is "sixteen million, one thousand, nine hundred ninety-nine".