638136 has 24 divisors (see below), whose sum is σ = 1728480. Its totient is φ = 212688.

The previous prime is 638123. The next prime is 638147. The reversal of 638136 is 631836.

It is a tau number, because it is divible by the number of its divisors (24).

It is a nude number because it is divisible by every one of its digits.

It is an Ulam number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 638136.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 4360 + ... + 4503.

It is an arithmetic number, because the mean of its divisors is an integer number (72020).

2⁶³⁸¹³⁶ is an apocalyptic number.

It is an amenable number.

638136 is an abundant number, since it is smaller than the sum of its proper divisors (1090344).

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

638136 is a wasteful number, since it uses less digits than its factorization.

638136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8875 (or 8868 counting only the distinct ones).

The product of its digits is 2592, while the sum is 27.

The square root of 638136 is about 798.8341504968. The cubic root of 638136 is about 86.0936423654.

It can be divided in two parts, 638 and 136, that multiplied together give a palindrome (86768).

The spelling of 638136 in words is "six hundred thirty-eight thousand, one hundred thirty-six".