6649979 has 4 divisors (see below), whose sum is σ = 7599984. Its totient is φ = 5699976.

The previous prime is 6649919. The next prime is 6649999. The reversal of 6649979 is 9799466.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9799466 = 2 ⋅4899733.

It is a cyclic number.

It is not a de Polignac number, because 6649979 - 2⁸ = 6649723 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6649919) 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, 474992 + ... + 475005.

It is an arithmetic number, because the mean of its divisors is an integer number (1899996).

Almost surely, 2^6649979 is an apocalyptic number.

6649979 is a deficient number, since it is larger than the sum of its proper divisors (950005).

6649979 is an equidigital number, since it uses as much as digits as its factorization.

6649979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 950004.

The product of its digits is 734832, while the sum is 50.

The square root of 6649979 is about 2578.7553199170. The cubic root of 6649979 is about 188.0500376090.

The spelling of 6649979 in words is "six million, six hundred forty-nine thousand, nine hundred seventy-nine".