21241413421 has 2 divisors, whose sum is σ = 21241413422. Its totient is φ = 21241413420.

The previous prime is 21241413377. The next prime is 21241413443. The reversal of 21241413421 is 12431414212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11877948196 + 9363465225 = 108986^2 + 96765^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21241413421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21241416421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10620706710 + 10620706711.

It is an arithmetic number, because the mean of its divisors is an integer number (10620706711).

Almost surely, 2^21241413421 is an apocalyptic number.

It is an amenable number.

21241413421 is a deficient number, since it is larger than the sum of its proper divisors (1).

21241413421 is an equidigital number, since it uses as much as digits as its factorization.

21241413421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1536, while the sum is 25.

Adding to 21241413421 its reverse (12431414212), we get a palindrome (33672827633).

The spelling of 21241413421 in words is "twenty-one billion, two hundred forty-one million, four hundred thirteen thousand, four hundred twenty-one".