2991999 has 4 divisors (see below), whose sum is σ = 3989336. Its totient is φ = 1994664.

The previous prime is 2991971. The next prime is 2992007. The reversal of 2991999 is 9991992.

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

It is not a de Polignac number, because 2991999 - 2⁷ = 2991871 is a prime.

It is a D-number.

It is a Duffinian number.

2991999 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2991929) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 498664 + ... + 498669.

It is an arithmetic number, because the mean of its divisors is an integer number (997334).

2^2991999 is an apocalyptic number.

2991999 is a deficient number, since it is larger than the sum of its proper divisors (997337).

2991999 is an equidigital number, since it uses as much as digits as its factorization.

2991999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 997336.

The product of its digits is 118098, while the sum is 48.

The square root of 2991999 is about 1729.7395757743. The cubic root of 2991999 is about 144.0966268907.

The spelling of 2991999 in words is "two million, nine hundred ninety-one thousand, nine hundred ninety-nine".