6621679 has 4 divisors (see below), whose sum is σ = 6628576. Its totient is φ = 6614784.

The previous prime is 6621649. The next prime is 6621691. The reversal of 6621679 is 9761266.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6621679 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 (6621649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1719 + ... + 4024.

It is an arithmetic number, because the mean of its divisors is an integer number (1657144).

Almost surely, 2^6621679 is an apocalyptic number.

6621679 is a deficient number, since it is larger than the sum of its proper divisors (6897).

6621679 is a wasteful number, since it uses less digits than its factorization.

6621679 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6896.

The product of its digits is 27216, while the sum is 37.

The square root of 6621679 is about 2573.2623263088. The cubic root of 6621679 is about 187.7828997613.

The spelling of 6621679 in words is "six million, six hundred twenty-one thousand, six hundred seventy-nine".