7998209 has 4 divisors (see below), whose sum is σ = 8042580. Its totient is φ = 7953840.

The previous prime is 7998169. The next prime is 7998223. The reversal of 7998209 is 9028997.

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

It can be written as a sum of positive squares in 2 ways, for example, as 73984 + 7924225 = 272^2 + 2815^2 .

It is a cyclic number.

It is not a de Polignac number, because 7998209 - 2¹² = 7994113 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 7998209.

It is not an unprimeable number, because it can be changed into a prime (7998269) 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, 21914 + ... + 22275.

It is an arithmetic number, because the mean of its divisors is an integer number (2010645).

Almost surely, 2^7998209 is an apocalyptic number.

It is an amenable number.

7998209 is a deficient number, since it is larger than the sum of its proper divisors (44371).

7998209 is a wasteful number, since it uses less digits than its factorization.

7998209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44370.

The product of its (nonzero) digits is 81648, while the sum is 44.

The square root of 7998209 is about 2828.1104999628. The cubic root of 7998209 is about 199.9850738861.

The spelling of 7998209 in words is "seven million, nine hundred ninety-eight thousand, two hundred nine".