21123311023 has 2 divisors, whose sum is σ = 21123311024. Its totient is φ = 21123311022.

The previous prime is 21123311017. The next prime is 21123311029. The reversal of 21123311023 is 32011332112.

It is a balanced prime because it is at equal distance from previous prime (21123311017) and next prime (21123311029).

It is a cyclic number.

It is not a de Polignac number, because 21123311023 - 2¹³ = 21123302831 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21123311029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10561655511 + 10561655512.

It is an arithmetic number, because the mean of its divisors is an integer number (10561655512).

Almost surely, 2^21123311023 is an apocalyptic number.

21123311023 is a deficient number, since it is larger than the sum of its proper divisors (1).

21123311023 is an equidigital number, since it uses as much as digits as its factorization.

21123311023 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21123311023 its reverse (32011332112), we get a palindrome (53134643135).

The spelling of 21123311023 in words is "twenty-one billion, one hundred twenty-three million, three hundred eleven thousand, twenty-three".