7999939 has 4 divisors (see below), whose sum is σ = 8024440. Its totient is φ = 7975440.

The previous prime is 7999921. The next prime is 7999963. The reversal of 7999939 is 9399997.

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

It is a cyclic number.

It is not a de Polignac number, because 7999939 - 2⁷ = 7999811 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 7999939.

It is not an unprimeable number, because it can be changed into a prime (7999909) 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 3 ways as a sum of consecutive naturals, for example, 11754 + ... + 12415.

It is an arithmetic number, because the mean of its divisors is an integer number (2006110).

Almost surely, 2^7999939 is an apocalyptic number.

7999939 is a deficient number, since it is larger than the sum of its proper divisors (24501).

7999939 is a wasteful number, since it uses less digits than its factorization.

7999939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24500.

The product of its digits is 1240029, while the sum is 55.

The square root of 7999939 is about 2828.4163413472. The cubic root of 7999939 is about 199.9994916654. Note that the first 3 decimals are identical.

The spelling of 7999939 in words is "seven million, nine hundred ninety-nine thousand, nine hundred thirty-nine".