6642111709 has 4 divisors (see below), whose sum is σ = 6642764604. Its totient is φ = 6641458816.

The previous prime is 6642111689. The next prime is 6642111727. The reversal of 6642111709 is 9071112466.

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 1028805625 + 5613306084 = 32075^2 + 74922^2 .

It is a cyclic number.

It is not a de Polignac number, because 6642111709 - 2²³ = 6633723101 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 (6642111779) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 310942 + ... + 331615.

It is an arithmetic number, because the mean of its divisors is an integer number (1660691151).

Almost surely, 2^6642111709 is an apocalyptic number.

It is an amenable number.

6642111709 is a deficient number, since it is larger than the sum of its proper divisors (652895).

6642111709 is a wasteful number, since it uses less digits than its factorization.

6642111709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 652894.

The product of its (nonzero) digits is 18144, while the sum is 37.

The square root of 6642111709 is about 81499.1515845411. The cubic root of 6642111709 is about 1879.7585049881.

The spelling of 6642111709 in words is "six billion, six hundred forty-two million, one hundred eleven thousand, seven hundred nine".