21123332369 has 2 divisors, whose sum is σ = 21123332370. Its totient is φ = 21123332368.

The previous prime is 21123332317. The next prime is 21123332381. The reversal of 21123332369 is 96323332112.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14771242369 + 6352090000 = 121537^2 + 79700^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21123332369 is a prime.

It is a super-2 number, since 2×21123332369² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21123332569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10561666184 + 10561666185.

It is an arithmetic number, because the mean of its divisors is an integer number (10561666185).

Almost surely, 2^21123332369 is an apocalyptic number.

It is an amenable number.

21123332369 is a deficient number, since it is larger than the sum of its proper divisors (1).

21123332369 is an equidigital number, since it uses as much as digits as its factorization.

21123332369 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34992, while the sum is 35.

The spelling of 21123332369 in words is "twenty-one billion, one hundred twenty-three million, three hundred thirty-two thousand, three hundred sixty-nine".