21000124443253 has 2 divisors, whose sum is σ = 21000124443254. Its totient is φ = 21000124443252.

The previous prime is 21000124443197. The next prime is 21000124443283. The reversal of 21000124443253 is 35234442100012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11972755667889 + 9027368775364 = 3460167^2 + 3004558^2 .

It is a cyclic number.

It is not a de Polignac number, because 21000124443253 - 2⁹ = 21000124442741 is a prime.

It is a super-2 number, since 2×21000124443253² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21000124443283) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500062221626 + 10500062221627.

It is an arithmetic number, because the mean of its divisors is an integer number (10500062221627).

Almost surely, 2^{21000124443253} is an apocalyptic number.

It is an amenable number.

21000124443253 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000124443253 is an equidigital number, since it uses as much as digits as its factorization.

21000124443253 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23040, while the sum is 31.

Adding to 21000124443253 its reverse (35234442100012), we get a palindrome (56234566543265).

The spelling of 21000124443253 in words is "twenty-one trillion, one hundred twenty-four million, four hundred forty-three thousand, two hundred fifty-three".