21113410121 has 2 divisors, whose sum is σ = 21113410122. Its totient is φ = 21113410120.

The previous prime is 21113410079. The next prime is 21113410127. The reversal of 21113410121 is 12101431112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15327678025 + 5785732096 = 123805^2 + 76064^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21113410121 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21113410121.

It is not a weakly prime, because it can be changed into another prime (21113410127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556705060 + 10556705061.

It is an arithmetic number, because the mean of its divisors is an integer number (10556705061).

Almost surely, 2^21113410121 is an apocalyptic number.

It is an amenable number.

21113410121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21113410121 is an equidigital number, since it uses as much as digits as its factorization.

21113410121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48, while the sum is 17.

Adding to 21113410121 its reverse (12101431112), we get a palindrome (33214841233).

The spelling of 21113410121 in words is "twenty-one billion, one hundred thirteen million, four hundred ten thousand, one hundred twenty-one".