6636389 has 4 divisors (see below), whose sum is σ = 6865260. Its totient is φ = 6407520.

The previous prime is 6636359. The next prime is 6636433. The reversal of 6636389 is 9836366.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9836366 = 2 ⋅4918183.

It can be written as a sum of positive squares in 2 ways, for example, as 2696164 + 3940225 = 1642^2 + 1985^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6636389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6636359) 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, 114392 + ... + 114449.

It is an arithmetic number, because the mean of its divisors is an integer number (1716315).

Almost surely, 2^6636389 is an apocalyptic number.

It is an amenable number.

6636389 is a deficient number, since it is larger than the sum of its proper divisors (228871).

6636389 is a wasteful number, since it uses less digits than its factorization.

6636389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228870.

The product of its digits is 139968, while the sum is 41.

The square root of 6636389 is about 2576.1189801715. The cubic root of 6636389 is about 187.9218495912.

The spelling of 6636389 in words is "six million, six hundred thirty-six thousand, three hundred eighty-nine".