2421 has 6 divisors (see below), whose sum is σ = 3510. Its totient is φ = 1608.
The previous prime is 2417. The next prime is 2423. The reversal of 2421 is 1242.
2421 is an esthetic number in base 8, because in such base its adjacent digits differ by 1.
It can be written as a sum of positive squares in only one way, i.e., 1521 + 900 = 39^2 + 30^2 .
It is not a de Polignac number, because 2421 - 22 = 2417 is a prime.
It is a super-2 number, since 2×24212 = 11722482, which contains 22 as substring.
It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 269 = 2421 / (2 + 4 + 2 + 1).
It is a plaindrome in base 12.
It is a nialpdrome in base 16.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (2423) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (7) of ones.
It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 126 + ... + 143.
It is an arithmetic number, because the mean of its divisors is an integer number (585).
It is an amenable number.
2421 is a deficient number, since it is larger than the sum of its proper divisors (1089).
2421 is a wasteful number, since it uses less digits than its factorization.
2421 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 275 (or 272 counting only the distinct ones).
The product of its digits is 16, while the sum is 9.
The square root of 2421 is about 49.2036584006. The cubic root of 2421 is about 13.4275959109.
Adding to 2421 its reverse (1242), we get a palindrome (3663).
It can be divided in two parts, 242 and 1, that added together give a 5-th power (243 = 35).
The spelling of 2421 in words is "two thousand, four hundred twenty-one", and thus it is an iban number.
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