6644641 has 4 divisors (see below), whose sum is σ = 6653872. Its totient is φ = 6635412.

The previous prime is 6644621. The next prime is 6644647. The reversal of 6644641 is 1464466.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1464466 = 2 ⋅732233.

It is a cyclic number.

It is not a de Polignac number, because 6644641 - 2¹¹ = 6642593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6644647) 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 3 ways as a sum of consecutive naturals, for example, 3435 + ... + 5008.

It is an arithmetic number, because the mean of its divisors is an integer number (1663468).

Almost surely, 2^6644641 is an apocalyptic number.

It is an amenable number.

6644641 is a deficient number, since it is larger than the sum of its proper divisors (9231).

6644641 is an equidigital number, since it uses as much as digits as its factorization.

6644641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9230.

The product of its digits is 13824, while the sum is 31.

The square root of 6644641 is about 2577.7201166923. The cubic root of 6644641 is about 187.9997076350. Note that the first 3 decimals are identical.

Adding to 6644641 its sum of digits (31), we get a cube (6644672 = 188³).

The spelling of 6644641 in words is "six million, six hundred forty-four thousand, six hundred forty-one".