21123773329 has 2 divisors, whose sum is σ = 21123773330. Its totient is φ = 21123773328.

The previous prime is 21123773299. The next prime is 21123773357. The reversal of 21123773329 is 92337732112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21117902400 + 5870929 = 145320^2 + 2423^2 .

It is a cyclic number.

It is not a de Polignac number, because 21123773329 - 2¹¹ = 21123771281 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21123773291 and 21123773300.

It is not a weakly prime, because it can be changed into another prime (21123773369) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10561886664 + 10561886665.

It is an arithmetic number, because the mean of its divisors is an integer number (10561886665).

Almost surely, 2^21123773329 is an apocalyptic number.

It is an amenable number.

21123773329 is a deficient number, since it is larger than the sum of its proper divisors (1).

21123773329 is an equidigital number, since it uses as much as digits as its factorization.

21123773329 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 95256, while the sum is 40.

The spelling of 21123773329 in words is "twenty-one billion, one hundred twenty-three million, seven hundred seventy-three thousand, three hundred twenty-nine".