21123234241 has 2 divisors, whose sum is σ = 21123234242. Its totient is φ = 21123234240.

The previous prime is 21123234157. The next prime is 21123234257. The reversal of 21123234241 is 14243232112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16769214016 + 4354020225 = 129496^2 + 65985^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21123234241 is a prime.

It is not a weakly prime, because it can be changed into another prime (21123234841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10561617120 + 10561617121.

It is an arithmetic number, because the mean of its divisors is an integer number (10561617121).

Almost surely, 2^21123234241 is an apocalyptic number.

It is an amenable number.

21123234241 is a deficient number, since it is larger than the sum of its proper divisors (1).

21123234241 is an equidigital number, since it uses as much as digits as its factorization.

21123234241 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2304, while the sum is 25.

Adding to 21123234241 its reverse (14243232112), we get a palindrome (35366466353).

The spelling of 21123234241 in words is "twenty-one billion, one hundred twenty-three million, two hundred thirty-four thousand, two hundred forty-one".