6636409 has 8 divisors (see below), whose sum is σ = 7567560. Its totient is φ = 5765376.

The previous prime is 6636359. The next prime is 6636433. The reversal of 6636409 is 9046366.

It can be written as a sum of positive squares in 4 ways, for example, as 2624400 + 4012009 = 1620^2 + 2003^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6636409 - 2⁹ = 6635897 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6636479) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14794 + ... + 15235.

It is an arithmetic number, because the mean of its divisors is an integer number (945945).

Almost surely, 2^6636409 is an apocalyptic number.

It is an amenable number.

6636409 is a deficient number, since it is larger than the sum of its proper divisors (931151).

6636409 is a wasteful number, since it uses less digits than its factorization.

6636409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30059.

The product of its (nonzero) digits is 23328, while the sum is 34.

The square root of 6636409 is about 2576.1228619769. The cubic root of 6636409 is about 187.9220383702.

The spelling of 6636409 in words is "six million, six hundred thirty-six thousand, four hundred nine".