5621 has 8 divisors (see below), whose sum is σ = 7104. Its totient is φ = 4320.

The previous prime is 5591. The next prime is 5623. The reversal of 5621 is 1265.

5621 is nontrivially palindromic in base 2.

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

It is a cyclic number.

It is not a de Polignac number, because 5621 - 2⁶ = 5557 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a zygodrome in base 4.

It is a junction number, because it is equal to n+sod(n) for n = 5596 and 5605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5623) 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, 41 + ... + 113.

It is an arithmetic number, because the mean of its divisors is an integer number (888).

2⁵⁶²¹ is an apocalyptic number.

It is an amenable number.

5621 is a deficient number, since it is larger than the sum of its proper divisors (1483).

5621 is a wasteful number, since it uses less digits than its factorization.

5621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91.

The product of its digits is 60, while the sum is 14.

The square root of 5621 is about 74.9733285909. The cubic root of 5621 is about 17.7802499456.

Adding to 5621 its reverse (1265), we get a palindrome (6886).

Subtracting from 5621 its reverse (1265), we obtain a square (4356 = 66²).

It can be divided in two parts, 56 and 21, that multiplied together give a triangular number (1176 = T₄₈).

The spelling of 5621 in words is "five thousand, six hundred twenty-one".