21243123301 has 2 divisors, whose sum is σ = 21243123302. Its totient is φ = 21243123300.

The previous prime is 21243123257. The next prime is 21243123329. The reversal of 21243123301 is 10332134212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16916904225 + 4326219076 = 130065^2 + 65774^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21243123301 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21243123371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10621561650 + 10621561651.

It is an arithmetic number, because the mean of its divisors is an integer number (10621561651).

Almost surely, 2^21243123301 is an apocalyptic number.

It is an amenable number.

21243123301 is a deficient number, since it is larger than the sum of its proper divisors (1).

21243123301 is an equidigital number, since it uses as much as digits as its factorization.

21243123301 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 22.

Adding to 21243123301 its reverse (10332134212), we get a palindrome (31575257513).

The spelling of 21243123301 in words is "twenty-one billion, two hundred forty-three million, one hundred twenty-three thousand, three hundred one".