6403638 has 16 divisors (see below), whose sum is σ = 12841200. Its totient is φ = 2128896.

The previous prime is 6403601. The next prime is 6403643. The reversal of 6403638 is 8363046.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1506 + ... + 3882.

It is an arithmetic number, because the mean of its divisors is an integer number (802575).

Almost surely, 2^6403638 is an apocalyptic number.

6403638 is an abundant number, since it is smaller than the sum of its proper divisors (6437562).

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

6403638 is a wasteful number, since it uses less digits than its factorization.

6403638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2831.

The product of its (nonzero) digits is 10368, while the sum is 30.

The square root of 6403638 is about 2530.5410488668. The cubic root of 6403638 is about 185.6987260562.

It can be divided in two parts, 640 and 3638, that added together give a triangular number (4278 = T₉₂).

The spelling of 6403638 in words is "six million, four hundred three thousand, six hundred thirty-eight".