6640501979 has 10 divisors (see below), whose sum is σ = 6819259260. Its totient is φ = 6464572932.

The previous prime is 6640501961. The next prime is 6640501993. The reversal of 6640501979 is 9791050466.

6640501979 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a de Polignac number, because none of the positive numbers 2^k-6640501979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6640501939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 64470842 + ... + 64470944.

It is an arithmetic number, because the mean of its divisors is an integer number (681925926).

Almost surely, 2^6640501979 is an apocalyptic number.

6640501979 is a deficient number, since it is larger than the sum of its proper divisors (178757281).

6640501979 is an frugal number, since it uses more digits than its factorization.

6640501979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 471 (or 162 counting only the distinct ones).

The product of its (nonzero) digits is 408240, while the sum is 47.

The square root of 6640501979 is about 81489.2752391381. The cubic root of 6640501979 is about 1879.6066382190.

The spelling of 6640501979 in words is "six billion, six hundred forty million, five hundred one thousand, nine hundred seventy-nine".