7989999 has 8 divisors (see below), whose sum is σ = 10666752. Its totient is φ = 5319960.

The previous prime is 7989973. The next prime is 7990001. The reversal of 7989999 is 9999897.

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

It is not a de Polignac number, because 7989999 - 2¹³ = 7981807 is a prime.

7989999 is a modest number, since divided by 9999 gives 798 as remainder.

7989999 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7989929) 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 7 ways as a sum of consecutive naturals, for example, 2842 + ... + 4904.

It is an arithmetic number, because the mean of its divisors is an integer number (1333344).

Almost surely, 2^7989999 is an apocalyptic number.

7989999 is a deficient number, since it is larger than the sum of its proper divisors (2676753).

7989999 is a wasteful number, since it uses less digits than its factorization.

7989999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3357.

The product of its digits is 3306744, while the sum is 60.

The square root of 7989999 is about 2826.6586281332. The cubic root of 7989999 is about 199.9166235800.

The spelling of 7989999 in words is "seven million, nine hundred eighty-nine thousand, nine hundred ninety-nine".