679131209 has 4 divisors (see below), whose sum is σ = 679268304. Its totient is φ = 678994116.

The previous prime is 679131203. The next prime is 679131217. The reversal of 679131209 is 902131976.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 679131209 - 2⁸ = 679130953 is a prime.

It is a super-2 number, since 2×679131209² = 922438398075603362, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (679131203) 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, 60827 + ... + 71120.

It is an arithmetic number, because the mean of its divisors is an integer number (169817076).

Almost surely, 2^679131209 is an apocalyptic number.

It is an amenable number.

679131209 is a deficient number, since it is larger than the sum of its proper divisors (137095).

679131209 is a wasteful number, since it uses less digits than its factorization.

679131209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137094.

The product of its (nonzero) digits is 20412, while the sum is 38.

The square root of 679131209 is about 26060.1459896141. The cubic root of 679131209 is about 878.9912722723.

The spelling of 679131209 in words is "six hundred seventy-nine million, one hundred thirty-one thousand, two hundred nine".