61638 has 8 divisors (see below), whose sum is σ = 123288. Its totient is φ = 20544.

The previous prime is 61637. The next prime is 61643. The reversal of 61638 is 83616.

61638 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

61638 is an admirable number.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5131 + ... + 5142.

It is an arithmetic number, because the mean of its divisors is an integer number (15411).

2⁶¹⁶³⁸ is an apocalyptic number.

61638 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.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (61644).

61638 is a wasteful number, since it uses less digits than its factorization.

61638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10278.

The product of its digits is 864, while the sum is 24.

The square root of 61638 is about 248.2700142989. The cubic root of 61638 is about 39.5017357567.

The spelling of 61638 in words is "sixty-one thousand, six hundred thirty-eight".