6616621 has 16 divisors (see below), whose sum is σ = 7838208. Its totient is φ = 5516800.

The previous prime is 6616607. The next prime is 6616637. The reversal of 6616621 is 1266166.

It is a cyclic number.

It is not a de Polignac number, because 6616621 - 2¹⁵ = 6583853 is a prime.

It is a Duffinian number.

6616621 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 6616621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6616601) 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 15 ways as a sum of consecutive naturals, for example, 7236 + ... + 8098.

It is an arithmetic number, because the mean of its divisors is an integer number (489888).

Almost surely, 2^6616621 is an apocalyptic number.

It is an amenable number.

6616621 is a deficient number, since it is larger than the sum of its proper divisors (1221587).

6616621 is a wasteful number, since it uses less digits than its factorization.

6616621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 932.

The product of its digits is 2592, while the sum is 28.

The square root of 6616621 is about 2572.2793394186. The cubic root of 6616621 is about 187.7350746379.

The spelling of 6616621 in words is "six million, six hundred sixteen thousand, six hundred twenty-one".