21221121241 has 2 divisors, whose sum is σ = 21221121242. Its totient is φ = 21221121240.

The previous prime is 21221121167. The next prime is 21221121283. The reversal of 21221121241 is 14212112212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11576899216 + 9644222025 = 107596^2 + 98205^2 .

It is a cyclic number.

It is not a de Polignac number, because 21221121241 - 2²³ = 21212732633 is a prime.

It is not a weakly prime, because it can be changed into another prime (21221121041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610560620 + 10610560621.

It is an arithmetic number, because the mean of its divisors is an integer number (10610560621).

Almost surely, 2^21221121241 is an apocalyptic number.

It is an amenable number.

21221121241 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221121241 is an equidigital number, since it uses as much as digits as its factorization.

21221121241 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 128, while the sum is 19.

Adding to 21221121241 its reverse (14212112212), we get a palindrome (35433233453).

The spelling of 21221121241 in words is "twenty-one billion, two hundred twenty-one million, one hundred twenty-one thousand, two hundred forty-one".