21234541 has 2 divisors, whose sum is σ = 21234542. Its totient is φ = 21234540.

The previous prime is 21234529. The next prime is 21234593. The reversal of 21234541 is 14543212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17015625 + 4218916 = 4125^2 + 2054^2 .

It is a cyclic number.

It is not a de Polignac number, because 21234541 - 2⁵ = 21234509 is a prime.

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

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21234841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10617270 + 10617271.

It is an arithmetic number, because the mean of its divisors is an integer number (10617271).

Almost surely, 2^21234541 is an apocalyptic number.

It is an amenable number.

21234541 is a deficient number, since it is larger than the sum of its proper divisors (1).

21234541 is an equidigital number, since it uses as much as digits as its factorization.

21234541 is an evil number, because the sum of its binary digits is even.

The product of its digits is 960, while the sum is 22.

The square root of 21234541 is about 4608.0951596077. The cubic root of 21234541 is about 276.9157298165.

Adding to 21234541 its reverse (14543212), we get a palindrome (35777753).

The spelling of 21234541 in words is "twenty-one million, two hundred thirty-four thousand, five hundred forty-one".