21113111423 has 2 divisors, whose sum is σ = 21113111424. Its totient is φ = 21113111422.

The previous prime is 21113111401. The next prime is 21113111443. The reversal of 21113111423 is 32411131112.

It is an a-pointer prime, because the next prime (21113111443) can be obtained adding 21113111423 to its sum of digits (20).

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21113111423 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21113111395 and 21113111404.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21113111443) 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, 10556555711 + 10556555712.

It is an arithmetic number, because the mean of its divisors is an integer number (10556555712).

Almost surely, 2^21113111423 is an apocalyptic number.

21113111423 is a deficient number, since it is larger than the sum of its proper divisors (1).

21113111423 is an equidigital number, since it uses as much as digits as its factorization.

21113111423 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 144, while the sum is 20.

Adding to 21113111423 its reverse (32411131112), we get a palindrome (53524242535).

The spelling of 21113111423 in words is "twenty-one billion, one hundred thirteen million, one hundred eleven thousand, four hundred twenty-three".