21433541 has 2 divisors, whose sum is σ = 21433542. Its totient is φ = 21433540.

The previous prime is 21433519. The next prime is 21433553. The reversal of 21433541 is 14533412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15288100 + 6145441 = 3910^2 + 2479^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21433541 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21433561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10716770 + 10716771.

It is an arithmetic number, because the mean of its divisors is an integer number (10716771).

Almost surely, 2^21433541 is an apocalyptic number.

It is an amenable number.

21433541 is a deficient number, since it is larger than the sum of its proper divisors (1).

21433541 is an equidigital number, since it uses as much as digits as its factorization.

21433541 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1440, while the sum is 23.

The square root of 21433541 is about 4629.6372428086. The cubic root of 21433541 is about 277.7780823049.

Adding to 21433541 its reverse (14533412), we get a palindrome (35966953).

The spelling of 21433541 in words is "twenty-one million, four hundred thirty-three thousand, five hundred forty-one".