21101311123 has 2 divisors, whose sum is σ = 21101311124. Its totient is φ = 21101311122.

The previous prime is 21101311117. The next prime is 21101311129. The reversal of 21101311123 is 32111310112.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (21101311117) and next prime (21101311129).

It is a cyclic number.

It is not a de Polignac number, because 21101311123 - 2²⁵ = 21067756691 is a prime.

It is a super-2 number, since 2×21101311123² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21101311097 and 21101311106.

It is not a weakly prime, because it can be changed into another prime (21101311129) 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, 10550655561 + 10550655562.

It is an arithmetic number, because the mean of its divisors is an integer number (10550655562).

Almost surely, 2^21101311123 is an apocalyptic number.

21101311123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21101311123 is an equidigital number, since it uses as much as digits as its factorization.

21101311123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36, while the sum is 16.

Adding to 21101311123 its reverse (32111310112), we get a palindrome (53212621235).

The spelling of 21101311123 in words is "twenty-one billion, one hundred one million, three hundred eleven thousand, one hundred twenty-three".