21234523 has 2 divisors, whose sum is σ = 21234524. Its totient is φ = 21234522.

The previous prime is 21234509. The next prime is 21234529. The reversal of 21234523 is 32543212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21234523 - 2⁹ = 21234011 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a junction number, because it is equal to n+sod(n) for n = 21234494 and 21234503.

It is not a weakly prime, because it can be changed into another prime (21234529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10617261 + 10617262.

It is an arithmetic number, because the mean of its divisors is an integer number (10617262).

Almost surely, 2^21234523 is an apocalyptic number.

21234523 is a deficient number, since it is larger than the sum of its proper divisors (1).

21234523 is an equidigital number, since it uses as much as digits as its factorization.

21234523 is an evil number, because the sum of its binary digits is even.

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

The square root of 21234523 is about 4608.0932065226. The cubic root of 21234523 is about 276.9156515716.

Adding to 21234523 its reverse (32543212), we get a palindrome (53777735).

The spelling of 21234523 in words is "twenty-one million, two hundred thirty-four thousand, five hundred twenty-three".