21351163502453 has 2 divisors, whose sum is σ = 21351163502454. Its totient is φ = 21351163502452.

The previous prime is 21351163502447. The next prime is 21351163502477. The reversal of 21351163502453 is 35420536115312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19625768289604 + 1725395212849 = 4430098^2 + 1313543^2 .

It is a cyclic number.

It is not a de Polignac number, because 21351163502453 - 2³⁴ = 21333983633269 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21351163502453.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21351163502413) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10675581751226 + 10675581751227.

It is an arithmetic number, because the mean of its divisors is an integer number (10675581751227).

Almost surely, 2^{21351163502453} is an apocalyptic number.

It is an amenable number.

21351163502453 is a deficient number, since it is larger than the sum of its proper divisors (1).

21351163502453 is an equidigital number, since it uses as much as digits as its factorization.

21351163502453 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 324000, while the sum is 41.

Adding to 21351163502453 its reverse (35420536115312), we get a palindrome (56771699617765).

The spelling of 21351163502453 in words is "twenty-one trillion, three hundred fifty-one billion, one hundred sixty-three million, five hundred two thousand, four hundred fifty-three".