64638 has 48 divisors (see below), whose sum is σ = 174720. Its totient is φ = 17496.

The previous prime is 64633. The next prime is 64661. The reversal of 64638 is 83646.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64633) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3393 + ... + 3411.

It is an arithmetic number, because the mean of its divisors is an integer number (3640).

2⁶⁴⁶³⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64638, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (87360).

64638 is an abundant number, since it is smaller than the sum of its proper divisors (110082).

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

64638 is a wasteful number, since it uses less digits than its factorization.

64638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43 (or 31 counting only the distinct ones).

The product of its digits is 3456, while the sum is 27.

The square root of 64638 is about 254.2400440529. The cubic root of 64638 is about 40.1324774256.

The spelling of 64638 in words is "sixty-four thousand, six hundred thirty-eight".