21375123520013 has 2 divisors, whose sum is σ = 21375123520014. Its totient is φ = 21375123520012.

The previous prime is 21375123519989. The next prime is 21375123520033. The reversal of 21375123520013 is 31002532157312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12961022420164 + 8414101099849 = 3600142^2 + 2900707^2 .

It is a cyclic number.

It is not a de Polignac number, because 21375123520013 - 2¹⁰ = 21375123518989 is a prime.

It is a super-2 number, since 2×21375123520013² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21375123520033) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10687561760006 + 10687561760007.

It is an arithmetic number, because the mean of its divisors is an integer number (10687561760007).

Almost surely, 2^{21375123520013} is an apocalyptic number.

It is an amenable number.

21375123520013 is a deficient number, since it is larger than the sum of its proper divisors (1).

21375123520013 is an equidigital number, since it uses as much as digits as its factorization.

21375123520013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 37800, while the sum is 35.

Adding to 21375123520013 its reverse (31002532157312), we get a palindrome (52377655677325).

The spelling of 21375123520013 in words is "twenty-one trillion, three hundred seventy-five billion, one hundred twenty-three million, five hundred twenty thousand, thirteen".