21121526616313 has 2 divisors, whose sum is σ = 21121526616314. Its totient is φ = 21121526616312.

The previous prime is 21121526616251. The next prime is 21121526616467. The reversal of 21121526616313 is 31361662512112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20993285276649 + 128241339664 = 4581843^2 + 358108^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21121526616313 is a prime.

It is a super-2 number, since 2×21121526616313² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21121526616713) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560763308156 + 10560763308157.

It is an arithmetic number, because the mean of its divisors is an integer number (10560763308157).

Almost surely, 2^{21121526616313} is an apocalyptic number.

It is an amenable number.

21121526616313 is a deficient number, since it is larger than the sum of its proper divisors (1).

21121526616313 is an equidigital number, since it uses as much as digits as its factorization.

21121526616313 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 77760, while the sum is 40.

The spelling of 21121526616313 in words is "twenty-one trillion, one hundred twenty-one billion, five hundred twenty-six million, six hundred sixteen thousand, three hundred thirteen".