6436638 has 64 divisors (see below), whose sum is σ = 15785280. Its totient is φ = 1931904.

The previous prime is 6436613. The next prime is 6436643. The reversal of 6436638 is 8366346.

6436638 is a `hidden beast` number, since 643 + 6 + 6 + 3 + 8 = 666.

6436638 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 37120 + ... + 37292.

It is an arithmetic number, because the mean of its divisors is an integer number (246645).

Almost surely, 2^6436638 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6436638, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7892640).

6436638 is an abundant number, since it is smaller than the sum of its proper divisors (9348642).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6436638 is a wasteful number, since it uses less digits than its factorization.

6436638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250 (or 244 counting only the distinct ones).

The product of its digits is 62208, while the sum is 36.

The square root of 6436638 is about 2537.0530148186. The cubic root of 6436638 is about 186.0171680303.

The spelling of 6436638 in words is "six million, four hundred thirty-six thousand, six hundred thirty-eight".