6638965 has 4 divisors (see below), whose sum is σ = 7966764. Its totient is φ = 5311168.

The previous prime is 6638953. The next prime is 6638977. The reversal of 6638965 is 5698366.

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

It is an interprime number because it is at equal distance from previous prime (6638953) and next prime (6638977).

It can be written as a sum of positive squares in 2 ways, for example, as 1912689 + 4726276 = 1383^2 + 2174^2 .

It is a cyclic number.

It is not a de Polignac number, because 6638965 - 2¹³ = 6630773 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 663892 + ... + 663901.

It is an arithmetic number, because the mean of its divisors is an integer number (1991691).

Almost surely, 2^6638965 is an apocalyptic number.

It is an amenable number.

6638965 is a deficient number, since it is larger than the sum of its proper divisors (1327799).

6638965 is a wasteful number, since it uses less digits than its factorization.

6638965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1327798.

The product of its digits is 233280, while the sum is 43.

The square root of 6638965 is about 2576.6189085699. The cubic root of 6638965 is about 187.9461612092.

The spelling of 6638965 in words is "six million, six hundred thirty-eight thousand, nine hundred sixty-five".