21303651236573 has 2 divisors, whose sum is σ = 21303651236574. Its totient is φ = 21303651236572.

The previous prime is 21303651236533. The next prime is 21303651236591. The reversal of 21303651236573 is 37563215630312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21213964763044 + 89686473529 = 4605862^2 + 299477^2 .

It is a cyclic number.

It is not a de Polignac number, because 21303651236573 - 2²⁰ = 21303650187997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21303651236533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10651825618286 + 10651825618287.

It is an arithmetic number, because the mean of its divisors is an integer number (10651825618287).

Almost surely, 2^{21303651236573} is an apocalyptic number.

It is an amenable number.

21303651236573 is a deficient number, since it is larger than the sum of its proper divisors (1).

21303651236573 is an equidigital number, since it uses as much as digits as its factorization.

21303651236573 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2041200, while the sum is 47.

Adding to 21303651236573 its reverse (37563215630312), we get a palindrome (58866866866885).

The spelling of 21303651236573 in words is "twenty-one trillion, three hundred three billion, six hundred fifty-one million, two hundred thirty-six thousand, five hundred seventy-three".