21311030123 has 2 divisors, whose sum is σ = 21311030124. Its totient is φ = 21311030122.

The previous prime is 21311030101. The next prime is 21311030183. The reversal of 21311030123 is 32103011312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21311030123 - 2⁸ = 21311029867 is a prime.

It is not a weakly prime, because it can be changed into another prime (21311030183) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10655515061 + 10655515062.

It is an arithmetic number, because the mean of its divisors is an integer number (10655515062).

Almost surely, 2^21311030123 is an apocalyptic number.

21311030123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21311030123 is an equidigital number, since it uses as much as digits as its factorization.

21311030123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108, while the sum is 17.

Adding to 21311030123 its reverse (32103011312), we get a palindrome (53414041435).

The spelling of 21311030123 in words is "twenty-one billion, three hundred eleven million, thirty thousand, one hundred twenty-three".