6618639 has 8 divisors (see below), whose sum is σ = 8864640. Its totient is φ = 4392536.

The previous prime is 6618617. The next prime is 6618653. The reversal of 6618639 is 9368166.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6618639 - 2⁷ = 6618511 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 6618597 and 6618606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6618659) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4179 + ... + 5540.

It is an arithmetic number, because the mean of its divisors is an integer number (1108080).

Almost surely, 2^6618639 is an apocalyptic number.

6618639 is a deficient number, since it is larger than the sum of its proper divisors (2246001).

6618639 is a wasteful number, since it uses less digits than its factorization.

6618639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9949.

The product of its digits is 46656, while the sum is 39.

The square root of 6618639 is about 2572.6715686228. The cubic root of 6618639 is about 187.7541584407.

The spelling of 6618639 in words is "six million, six hundred eighteen thousand, six hundred thirty-nine".