21303001253 has 2 divisors, whose sum is σ = 21303001254. Its totient is φ = 21303001252.

The previous prime is 21303001249. The next prime is 21303001289. The reversal of 21303001253 is 35210030312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18927706084 + 2375295169 = 137578^2 + 48737^2 .

It is a cyclic number.

It is not a de Polignac number, because 21303001253 - 2² = 21303001249 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21303001553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10651500626 + 10651500627.

It is an arithmetic number, because the mean of its divisors is an integer number (10651500627).

Almost surely, 2^21303001253 is an apocalyptic number.

It is an amenable number.

21303001253 is a deficient number, since it is larger than the sum of its proper divisors (1).

21303001253 is an equidigital number, since it uses as much as digits as its factorization.

21303001253 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 540, while the sum is 20.

Adding to 21303001253 its reverse (35210030312), we get a palindrome (56513031565).

The spelling of 21303001253 in words is "twenty-one billion, three hundred three million, one thousand, two hundred fifty-three".