6618821 has 12 divisors (see below), whose sum is σ = 7660800. Its totient is φ = 5698440.

The previous prime is 6618811. The next prime is 6618823. The reversal of 6618821 is 1288166.

It is not a de Polignac number, because 6618821 - 2¹⁰ = 6617797 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6618823) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 860 + ... + 3738.

It is an arithmetic number, because the mean of its divisors is an integer number (638400).

Almost surely, 2^6618821 is an apocalyptic number.

It is an amenable number.

6618821 is a deficient number, since it is larger than the sum of its proper divisors (1041979).

6618821 is a wasteful number, since it uses less digits than its factorization.

6618821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2920 (or 2909 counting only the distinct ones).

The product of its digits is 4608, while the sum is 32.

The square root of 6618821 is about 2572.7069401702. The cubic root of 6618821 is about 187.7558793858.

The spelling of 6618821 in words is "six million, six hundred eighteen thousand, eight hundred twenty-one".