21432413 has 2 divisors, whose sum is σ = 21432414. Its totient is φ = 21432412.

The previous prime is 21432409. The next prime is 21432443. The reversal of 21432413 is 31423412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20313049 + 1119364 = 4507^2 + 1058^2 .

It is a cyclic number.

It is not a de Polignac number, because 21432413 - 2² = 21432409 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21432403) 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, 10716206 + 10716207.

It is an arithmetic number, because the mean of its divisors is an integer number (10716207).

Almost surely, 2^21432413 is an apocalyptic number.

It is an amenable number.

21432413 is a deficient number, since it is larger than the sum of its proper divisors (1).

21432413 is an equidigital number, since it uses as much as digits as its factorization.

21432413 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 576, while the sum is 20.

The square root of 21432413 is about 4629.5154174060. The cubic root of 21432413 is about 277.7732092700.

Adding to 21432413 its reverse (31423412), we get a palindrome (52855825).

Subtracting 21432413 from its reverse (31423412), we obtain a palindrome (9990999).

The spelling of 21432413 in words is "twenty-one million, four hundred thirty-two thousand, four hundred thirteen".