21111613123 has 2 divisors, whose sum is σ = 21111613124. Its totient is φ = 21111613122.

The previous prime is 21111613049. The next prime is 21111613139. The reversal of 21111613123 is 32131611112.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21111613123 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21111613094 and 21111613103.

It is not a weakly prime, because it can be changed into another prime (21111613423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555806561 + 10555806562.

It is an arithmetic number, because the mean of its divisors is an integer number (10555806562).

Almost surely, 2^21111613123 is an apocalyptic number.

21111613123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111613123 is an equidigital number, since it uses as much as digits as its factorization.

21111613123 is an evil number, because the sum of its binary digits is even.

The product of its digits is 216, while the sum is 22.

The spelling of 21111613123 in words is "twenty-one billion, one hundred eleven million, six hundred thirteen thousand, one hundred twenty-three".