133638 has 8 divisors (see below), whose sum is σ = 267288. Its totient is φ = 44544.

The previous prime is 133633. The next prime is 133649. The reversal of 133638 is 836331.

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

133638 is an admirable number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11131 + ... + 11142.

It is an arithmetic number, because the mean of its divisors is an integer number (33411).

2¹³³⁶³⁸ is an apocalyptic number.

133638 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

133638 is a wasteful number, since it uses less digits than its factorization.

133638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22278.

The product of its digits is 1296, while the sum is 24.

The square root of 133638 is about 365.5653156414. The cubic root of 133638 is about 51.1261773830.

Adding to 133638 its reverse (836331), we get a palindrome (969969).

The spelling of 133638 in words is "one hundred thirty-three thousand, six hundred thirty-eight".