23421 has 8 divisors (see below), whose sum is σ = 32224. Its totient is φ = 15120.

The previous prime is 23417. The next prime is 23431. The reversal of 23421 is 12432.

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

It is not a de Polignac number, because 23421 - 2² = 23417 is a prime.

It is a Duffinian number.

23421 is a lucky number.

It is a plaindrome in base 12.

It is a junction number, because it is equal to n+sod(n) for n = 23397 and 23406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6 + ... + 216.

It is an arithmetic number, because the mean of its divisors is an integer number (4028).

2²³⁴²¹ is an apocalyptic number.

It is an amenable number.

23421 is a deficient number, since it is larger than the sum of its proper divisors (8803).

23421 is a wasteful number, since it uses less digits than its factorization.

23421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 251.

The product of its digits is 48, while the sum is 12.

The square root of 23421 is about 153.0392106618. The cubic root of 23421 is about 28.6111388304.

Subtracting from 23421 its sum of digits (12), we obtain a square (23409 = 153²).

Adding to 23421 its reverse (12432), we get a palindrome (35853).

It can be divided in two parts, 23 and 421, that added together give a palindrome (444).

The spelling of 23421 in words is "twenty-three thousand, four hundred twenty-one", and thus it is an iban number.