21542323 has 8 divisors (see below), whose sum is σ = 23832576. Its totient is φ = 19307400.

The previous prime is 21542321. The next prime is 21542341. The reversal of 21542323 is 32324512.

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 21542323 - 2¹ = 21542321 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21542294 and 21542303.

It is not an unprimeable number, because it can be changed into a prime (21542321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13011 + ... + 14572.

It is an arithmetic number, because the mean of its divisors is an integer number (2979072).

Almost surely, 2^21542323 is an apocalyptic number.

21542323 is a deficient number, since it is larger than the sum of its proper divisors (2290253).

21542323 is a wasteful number, since it uses less digits than its factorization.

21542323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27665.

The product of its digits is 1440, while the sum is 22.

The square root of 21542323 is about 4641.3708104395. The cubic root of 21542323 is about 278.2472267219.

Adding to 21542323 its reverse (32324512), we get a palindrome (53866835).

The spelling of 21542323 in words is "twenty-one million, five hundred forty-two thousand, three hundred twenty-three".