21343523 has 8 divisors (see below), whose sum is σ = 22150656. Its totient is φ = 20550600.

The previous prime is 21343519. The next prime is 21343579. The reversal of 21343523 is 32534312.

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 21343523 - 2² = 21343519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21343513) 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, 443 + ... + 6548.

It is an arithmetic number, because the mean of its divisors is an integer number (2768832).

Almost surely, 2^21343523 is an apocalyptic number.

21343523 is a deficient number, since it is larger than the sum of its proper divisors (807133).

21343523 is an equidigital number, since it uses as much as digits as its factorization.

21343523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7105.

The product of its digits is 2160, while the sum is 23.

The square root of 21343523 is about 4619.9050856051. The cubic root of 21343523 is about 277.3886597134.

Adding to 21343523 its reverse (32534312), we get a palindrome (53877835).

The spelling of 21343523 in words is "twenty-one million, three hundred forty-three thousand, five hundred twenty-three".