21234529 has 2 divisors, whose sum is σ = 21234530. Its totient is φ = 21234528.

The previous prime is 21234523. The next prime is 21234541. The reversal of 21234529 is 92543212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21160000 + 74529 = 4600^2 + 273^2 .

It is a cyclic number.

It is not a de Polignac number, because 21234529 - 2⁷ = 21234401 is a prime.

It is a Chen 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 = 21234497 and 21234506.

It is not a weakly prime, because it can be changed into another prime (21234523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10617264 + 10617265.

It is an arithmetic number, because the mean of its divisors is an integer number (10617265).

Almost surely, 2^21234529 is an apocalyptic number.

It is an amenable number.

21234529 is a deficient number, since it is larger than the sum of its proper divisors (1).

21234529 is an equidigital number, since it uses as much as digits as its factorization.

21234529 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 21234529 is about 4608.0938575511. The cubic root of 21234529 is about 276.9156776533.

The spelling of 21234529 in words is "twenty-one million, two hundred thirty-four thousand, five hundred twenty-nine".