61728 has 24 divisors (see below), whose sum is σ = 162288. Its totient is φ = 20544.

The previous prime is 61723. The next prime is 61729. The reversal of 61728 is 82716.

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

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a junction number, because it is equal to n+sod(n) for n = 61698 and 61707.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 61728.

It is not an unprimeable number, because it can be changed into a prime (61723) by changing a digit.

61728 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 226 + ... + 417.

It is an arithmetic number, because the mean of its divisors is an integer number (6762).

2⁶¹⁷²⁸ is an apocalyptic number.

It is an amenable number.

61728 is an abundant number, since it is smaller than the sum of its proper divisors (100560).

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 (81144).

61728 is a wasteful number, since it uses less digits than its factorization.

61728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 656 (or 648 counting only the distinct ones).

The product of its digits is 672, while the sum is 24.

The square root of 61728 is about 248.4512024523. The cubic root of 61728 is about 39.5209524048.

The spelling of 61728 in words is "sixty-one thousand, seven hundred twenty-eight".