6621681 has 8 divisors (see below), whose sum is σ = 9631584. Its totient is φ = 4013120.

The previous prime is 6621649. The next prime is 6621691. The reversal of 6621681 is 1861266.

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 6621681 - 2⁵ = 6621649 is a prime.

It is a super-2 number, since 2×6621681² = 87693318531522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (6621691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 100296 + ... + 100361.

It is an arithmetic number, because the mean of its divisors is an integer number (1203948).

Almost surely, 2^6621681 is an apocalyptic number.

It is an amenable number.

6621681 is a deficient number, since it is larger than the sum of its proper divisors (3009903).

6621681 is a wasteful number, since it uses less digits than its factorization.

6621681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 200671.

The product of its digits is 3456, while the sum is 30.

The square root of 6621681 is about 2573.2627149205. The cubic root of 6621681 is about 187.7829186672.

The spelling of 6621681 in words is "six million, six hundred twenty-one thousand, six hundred eighty-one".