6659995999 has 4 divisors (see below), whose sum is σ = 6694865280. Its totient is φ = 6625126720.

The previous prime is 6659995987. The next prime is 6659996003. The reversal of 6659995999 is 9995999566.

It is a happy number.

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 6659995999 - 2⁹ = 6659995487 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6659995099) 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, 17434354 + ... + 17434735.

It is an arithmetic number, because the mean of its divisors is an integer number (1673716320).

Almost surely, 2^6659995999 is an apocalyptic number.

6659995999 is a deficient number, since it is larger than the sum of its proper divisors (34869281).

6659995999 is a wasteful number, since it uses less digits than its factorization.

6659995999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34869280.

The product of its digits is 478296900, while the sum is 76.

The square root of 6659995999 is about 81608.7985391281. The cubic root of 6659995999 is about 1881.4441144143. Note that the first 3 decimals are identical.

The spelling of 6659995999 in words is "six billion, six hundred fifty-nine million, nine hundred ninety-five thousand, nine hundred ninety-nine".