21120012253 has 2 divisors, whose sum is σ = 21120012254. Its totient is φ = 21120012252.

The previous prime is 21120012197. The next prime is 21120012259. The reversal of 21120012253 is 35221002112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19745308324 + 1374703929 = 140518^2 + 37077^2 .

It is a cyclic number.

It is not a de Polignac number, because 21120012253 - 2⁹ = 21120011741 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21120012253.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21120012259) 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, 10560006126 + 10560006127.

It is an arithmetic number, because the mean of its divisors is an integer number (10560006127).

Almost surely, 2^21120012253 is an apocalyptic number.

It is an amenable number.

21120012253 is a deficient number, since it is larger than the sum of its proper divisors (1).

21120012253 is an equidigital number, since it uses as much as digits as its factorization.

21120012253 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 240, while the sum is 19.

Adding to 21120012253 its reverse (35221002112), we get a palindrome (56341014365).

The spelling of 21120012253 in words is "twenty-one billion, one hundred twenty million, twelve thousand, two hundred fifty-three".