6642979 has 6 divisors (see below), whose sum is σ = 7727604. Its totient is φ = 5693940.

The previous prime is 6642919. The next prime is 6642991. The reversal of 6642979 is 9792466.

It is a de Polignac number, because none of the positive numbers 2^k-6642979 is a prime.

It is a d-powerful number, because it can be written as 6⁶ + 6⁸ + 4⁴ + 2¹⁷ + 9 + 7⁴ + 9⁷ .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6642919) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 67737 + ... + 67834.

It is an arithmetic number, because the mean of its divisors is an integer number (1287934).

Almost surely, 2^6642979 is an apocalyptic number.

6642979 is a deficient number, since it is larger than the sum of its proper divisors (1084625).

6642979 is a wasteful number, since it uses less digits than its factorization.

6642979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135585 (or 135578 counting only the distinct ones).

The product of its digits is 163296, while the sum is 43.

The square root of 6642979 is about 2577.3977186302. The cubic root of 6642979 is about 187.9840317658.

The spelling of 6642979 in words is "six million, six hundred forty-two thousand, nine hundred seventy-nine".