21021121241 has 2 divisors, whose sum is σ = 21021121242. Its totient is φ = 21021121240.

The previous prime is 21021121201. The next prime is 21021121259. The reversal of 21021121241 is 14212112012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21014851225 + 6270016 = 144965^2 + 2504^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21021121241 is a prime.

It is not a weakly prime, because it can be changed into another prime (21021121201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510560620 + 10510560621.

It is an arithmetic number, because the mean of its divisors is an integer number (10510560621).

Almost surely, 2^21021121241 is an apocalyptic number.

It is an amenable number.

21021121241 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021121241 is an equidigital number, since it uses as much as digits as its factorization.

21021121241 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21021121241 its reverse (14212112012), we get a palindrome (35233233253).

The spelling of 21021121241 in words is "twenty-one billion, twenty-one million, one hundred twenty-one thousand, two hundred forty-one".