24421 has 2 divisors, whose sum is σ = 24422.
Its totient is φ = 24420.
The previous prime is 24419. The next prime is 24439. The reversal of 24421 is 12442.
24421 = 1102 + 1112.
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 12321 + 12100 = 111^2 + 110^2
It is a cyclic number.
It is not a de Polignac number, because 24421 - 21 = 24419 is a prime.
Together with 24419, it forms a pair of twin primes.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (24481) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12210 + 12211.
It is an arithmetic number, because the mean of its divisors is an integer number (12211).
224421 is an apocalyptic number.
24421 is the 111-st centered square number.
It is an amenable number.
24421 is a deficient number, since it is larger than the sum of its proper divisors (1).
24421 is an equidigital number, since it uses as much as digits as its factorization.
24421 is an evil number, because the sum of its binary digits is even.
The product of its digits is 64, while the sum is 13.
The square root of 24421 is about 156.2721984231.
The cubic root of 24421 is about 29.0126777704.
Adding to 24421 its reverse (12442), we get a palindrome (36863).
The spelling of 24421 in words is "twenty-four thousand, four hundred twenty-one", and thus it is an iban number.