28651 has 4 divisors (see below), whose sum is σ = 32752. Its totient is φ = 24552.

The previous prime is 28649. The next prime is 28657. The reversal of 28651 is 15682.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15682 = 2 ⋅7841.

It is a cyclic number.

It is not a de Polignac number, because 28651 - 2¹ = 28649 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (28657) 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, 2040 + ... + 2053.

It is an arithmetic number, because the mean of its divisors is an integer number (8188).

2²⁸⁶⁵¹ is an apocalyptic number.

28651 is a deficient number, since it is larger than the sum of its proper divisors (4101).

28651 is an equidigital number, since it uses as much as digits as its factorization.

28651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4100.

The product of its digits is 480, while the sum is 22.

The square root of 28651 is about 169.2660627533. The cubic root of 28651 is about 30.5994247119.

The spelling of 28651 in words is "twenty-eight thousand, six hundred fifty-one".