21203212253 has 2 divisors, whose sum is σ = 21203212254. Its totient is φ = 21203212252.

The previous prime is 21203212201. The next prime is 21203212273. The reversal of 21203212253 is 35221230212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18967624729 + 2235587524 = 137723^2 + 47282^2 .

It is a cyclic number.

It is not a de Polignac number, because 21203212253 - 2¹⁰ = 21203211229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21203212273) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601606126 + 10601606127.

It is an arithmetic number, because the mean of its divisors is an integer number (10601606127).

Almost surely, 2^21203212253 is an apocalyptic number.

It is an amenable number.

21203212253 is a deficient number, since it is larger than the sum of its proper divisors (1).

21203212253 is an equidigital number, since it uses as much as digits as its factorization.

21203212253 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1440, while the sum is 23.

Adding to 21203212253 its reverse (35221230212), we get a palindrome (56424442465).

The spelling of 21203212253 in words is "twenty-one billion, two hundred three million, two hundred twelve thousand, two hundred fifty-three".