21143423 has 8 divisors (see below), whose sum is σ = 24192000. Its totient is φ = 18101880.

The previous prime is 21143411. The next prime is 21143453. The reversal of 21143423 is 32434112.

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 21143423 - 2¹⁰ = 21142399 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21143395 and 21143404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21143453) 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, 9578 + ... + 11576.

It is an arithmetic number, because the mean of its divisors is an integer number (3024000).

Almost surely, 2^21143423 is an apocalyptic number.

21143423 is a deficient number, since it is larger than the sum of its proper divisors (3048577).

21143423 is a wasteful number, since it uses less digits than its factorization.

21143423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3517.

The product of its digits is 576, while the sum is 20.

The square root of 21143423 is about 4598.1977991383. The cubic root of 21143423 is about 276.5190775859.

Adding to 21143423 its reverse (32434112), we get a palindrome (53577535).

It can be divided in two parts, 211 and 43423, that added together give a palindrome (43634).

The spelling of 21143423 in words is "twenty-one million, one hundred forty-three thousand, four hundred twenty-three".