21123323153 has 2 divisors, whose sum is σ = 21123323154. Its totient is φ = 21123323152.

The previous prime is 21123323077. The next prime is 21123323189. The reversal of 21123323153 is 35132332112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20973701329 + 149621824 = 144823^2 + 12232^2 .

It is a cyclic number.

It is not a de Polignac number, because 21123323153 - 2⁸ = 21123322897 is a prime.

It is a super-2 number, since 2×21123323153² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21123323653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10561661576 + 10561661577.

It is an arithmetic number, because the mean of its divisors is an integer number (10561661577).

Almost surely, 2^21123323153 is an apocalyptic number.

It is an amenable number.

21123323153 is a deficient number, since it is larger than the sum of its proper divisors (1).

21123323153 is an equidigital number, since it uses as much as digits as its factorization.

21123323153 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3240, while the sum is 26.

Adding to 21123323153 its reverse (35132332112), we get a palindrome (56255655265).

The spelling of 21123323153 in words is "twenty-one billion, one hundred twenty-three million, three hundred twenty-three thousand, one hundred fifty-three".