6621641 has 8 divisors (see below), whose sum is σ = 7197960. Its totient is φ = 6054912.

The previous prime is 6621607. The next prime is 6621649. The reversal of 6621641 is 1461266.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2042041 + 4579600 = 1429^2 + 2140^2 .

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 6621641 - 2¹⁰ = 6620617 is a prime.

It is a super-2 number, since 2×6621641² = 87692259065762, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 6621641.

It is not an unprimeable number, because it can be changed into a prime (6621649) 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, 920 + ... + 3753.

It is an arithmetic number, because the mean of its divisors is an integer number (899745).

Almost surely, 2^6621641 is an apocalyptic number.

It is an amenable number.

6621641 is a deficient number, since it is larger than the sum of its proper divisors (576319).

6621641 is a wasteful number, since it uses less digits than its factorization.

6621641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4795.

The product of its digits is 1728, while the sum is 26.

The square root of 6621641 is about 2573.2549426747. The cubic root of 6621641 is about 187.7825405491.

The spelling of 6621641 in words is "six million, six hundred twenty-one thousand, six hundred forty-one".