28722 has 8 divisors (see below), whose sum is σ = 57456. Its totient is φ = 9572.

The previous prime is 28711. The next prime is 28723. The reversal of 28722 is 22782.

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

28722 is an admirable number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 28722.

It is not an unprimeable number, because it can be changed into a prime (28723) by changing a digit.

28722 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, 2388 + ... + 2399.

It is an arithmetic number, because the mean of its divisors is an integer number (7182).

2²⁸⁷²² is an apocalyptic number.

28722 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 (28728).

28722 is a wasteful number, since it uses less digits than its factorization.

28722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4792.

The product of its digits is 448, while the sum is 21.

The square root of 28722 is about 169.4756619695. The cubic root of 28722 is about 30.6246799911.

The spelling of 28722 in words is "twenty-eight thousand, seven hundred twenty-two".