21063645363253 has 4 divisors (see below), whose sum is σ = 21067815561408. Its totient is φ = 21059475165100.

The previous prime is 21063645363217. The next prime is 21063645363323. The reversal of 21063645363253 is 35236354636012.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21063645363253 - 2²⁵ = 21063611808821 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21063645363197 and 21063645363206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21063645363353) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2085091501 + ... + 2085101602.

It is an arithmetic number, because the mean of its divisors is an integer number (5266953890352).

Almost surely, 2^{21063645363253} is an apocalyptic number.

It is an amenable number.

21063645363253 is a deficient number, since it is larger than the sum of its proper divisors (4170198155).

21063645363253 is an equidigital number, since it uses as much as digits as its factorization.

21063645363253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4170198154.

The product of its (nonzero) digits is 6998400, while the sum is 49.

Adding to 21063645363253 its reverse (35236354636012), we get a palindrome (56299999999265).

The spelling of 21063645363253 in words is "twenty-one trillion, sixty-three billion, six hundred forty-five million, three hundred sixty-three thousand, two hundred fifty-three".