6688599949 has 4 divisors (see below), whose sum is σ = 6698938464. Its totient is φ = 6678261436.

The previous prime is 6688599937. The next prime is 6688599979. The reversal of 6688599949 is 9499958866.

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 6688599949 - 2⁵ = 6688599917 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 (6688599979) 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, 5168287 + ... + 5169580.

It is an arithmetic number, because the mean of its divisors is an integer number (1674734616).

Almost surely, 2^6688599949 is an apocalyptic number.

It is an amenable number.

6688599949 is a deficient number, since it is larger than the sum of its proper divisors (10338515).

6688599949 is a wasteful number, since it uses less digits than its factorization.

6688599949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10338514.

The product of its digits is 302330880, while the sum is 73.

The square root of 6688599949 is about 81783.8611768850. The cubic root of 6688599949 is about 1884.1337992652.

The spelling of 6688599949 in words is "six billion, six hundred eighty-eight million, five hundred ninety-nine thousand, nine hundred forty-nine".