21324529 has 2 divisors, whose sum is σ = 21324530. Its totient is φ = 21324528.

The previous prime is 21324509. The next prime is 21324533. The reversal of 21324529 is 92542312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17514225 + 3810304 = 4185^2 + 1952^2 .

It is a cyclic number.

It is not a de Polignac number, because 21324529 - 2¹¹ = 21322481 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21324497 and 21324506.

It is not a weakly prime, because it can be changed into another prime (21324509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10662264 + 10662265.

It is an arithmetic number, because the mean of its divisors is an integer number (10662265).

Almost surely, 2^21324529 is an apocalyptic number.

It is an amenable number.

21324529 is a deficient number, since it is larger than the sum of its proper divisors (1).

21324529 is an equidigital number, since it uses as much as digits as its factorization.

21324529 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4320, while the sum is 28.

The square root of 21324529 is about 4617.8489581189. The cubic root of 21324529 is about 277.3063508417.

It can be divided in two parts, 213 and 24529, that added together give a palindrome (24742).

The spelling of 21324529 in words is "twenty-one million, three hundred twenty-four thousand, five hundred twenty-nine".