61644 has 24 divisors (see below), whose sum is σ = 157248. Its totient is φ = 18640.

The previous prime is 61643. The next prime is 61651. The reversal of 61644 is 44616.

61644 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×61644³ = 702738407333952, which contains 333 as substring.

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

It is a zygodrome in base 2.

It is a self number, because there is not a number n which added to its sum of digits gives 61644.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 61644.

It is not an unprimeable number, because it can be changed into a prime (61643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 102 + ... + 365.

It is an arithmetic number, because the mean of its divisors is an integer number (6552).

2⁶¹⁶⁴⁴ is an apocalyptic number.

It is an amenable number.

61644 is an abundant number, since it is smaller than the sum of its proper divisors (95604).

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 (78624).

61644 is a wasteful number, since it uses less digits than its factorization.

61644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 485 (or 483 counting only the distinct ones).

The product of its digits is 576, while the sum is 21.

The square root of 61644 is about 248.2820976228. The cubic root of 61644 is about 39.5030174483.

The spelling of 61644 in words is "sixty-one thousand, six hundred forty-four".