21433589 has 2 divisors, whose sum is σ = 21433590. Its totient is φ = 21433588.

The previous prime is 21433561. The next prime is 21433597. The reversal of 21433589 is 98533412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10923025 + 10510564 = 3305^2 + 3242^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21433589 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21433519) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10716794 + 10716795.

It is an arithmetic number, because the mean of its divisors is an integer number (10716795).

Almost surely, 2^21433589 is an apocalyptic number.

It is an amenable number.

21433589 is a deficient number, since it is larger than the sum of its proper divisors (1).

21433589 is an equidigital number, since it uses as much as digits as its factorization.

21433589 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25920, while the sum is 35.

The square root of 21433589 is about 4629.6424267971. The cubic root of 21433589 is about 277.7782896642.

It can be divided in two parts, 21433 and 589, that added together give a palindrome (22022).

The spelling of 21433589 in words is "twenty-one million, four hundred thirty-three thousand, five hundred eighty-nine".