16051999 has 4 divisors (see below), whose sum is σ = 16749936. Its totient is φ = 15354064.

The previous prime is 16051991. The next prime is 16052027. The reversal of 16051999 is 99915061.

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

It is not a de Polignac number, because 16051999 - 2³ = 16051991 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16051991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 348934 + ... + 348979.

It is an arithmetic number, because the mean of its divisors is an integer number (4187484).

Almost surely, 2^16051999 is an apocalyptic number.

16051999 is a deficient number, since it is larger than the sum of its proper divisors (697937).

16051999 is an equidigital number, since it uses as much as digits as its factorization.

16051999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 697936.

The product of its (nonzero) digits is 21870, while the sum is 40.

The square root of 16051999 is about 4006.4946025173. The cubic root of 16051999 is about 252.2568924361.

The spelling of 16051999 in words is "sixteen million, fifty-one thousand, nine hundred ninety-nine".