6644545 has 4 divisors (see below), whose sum is σ = 7973460. Its totient is φ = 5315632.

The previous prime is 6644543. The next prime is 6644549. The reversal of 6644545 is 5454466.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1555009 + 5089536 = 1247^2 + 2256^2 .

It is a cyclic number.

It is not a de Polignac number, because 6644545 - 2¹ = 6644543 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6644545.

It is not an unprimeable number, because it can be changed into a prime (6644543) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 664450 + ... + 664459.

It is an arithmetic number, because the mean of its divisors is an integer number (1993365).

Almost surely, 2^6644545 is an apocalyptic number.

It is an amenable number.

6644545 is a deficient number, since it is larger than the sum of its proper divisors (1328915).

6644545 is a wasteful number, since it uses less digits than its factorization.

6644545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1328914.

The product of its digits is 57600, while the sum is 34.

The square root of 6644545 is about 2577.7014955188. The cubic root of 6644545 is about 187.9988022407.

The spelling of 6644545 in words is "six million, six hundred forty-four thousand, five hundred forty-five".