6631609 has 4 divisors (see below), whose sum is σ = 6670116. Its totient is φ = 6593104.

The previous prime is 6631607. The next prime is 6631619. The reversal of 6631609 is 9061366.

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 5359225 + 1272384 = 2315^2 + 1128^2 .

It is a cyclic number.

It is not a de Polignac number, because 6631609 - 2¹ = 6631607 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6631607) 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, 18994 + ... + 19339.

It is an arithmetic number, because the mean of its divisors is an integer number (1667529).

Almost surely, 2^6631609 is an apocalyptic number.

It is an amenable number.

6631609 is a deficient number, since it is larger than the sum of its proper divisors (38507).

6631609 is a wasteful number, since it uses less digits than its factorization.

6631609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38506.

The product of its (nonzero) digits is 5832, while the sum is 31.

The square root of 6631609 is about 2575.1910608730. The cubic root of 6631609 is about 187.8767205211.

The spelling of 6631609 in words is "six million, six hundred thirty-one thousand, six hundred nine".