21123034111 has 2 divisors, whose sum is σ = 21123034112. Its totient is φ = 21123034110.

The previous prime is 21123034061. The next prime is 21123034117. The reversal of 21123034111 is 11143032112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21123034111 - 2¹³ = 21123025919 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21123034117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10561517055 + 10561517056.

It is an arithmetic number, because the mean of its divisors is an integer number (10561517056).

Almost surely, 2^21123034111 is an apocalyptic number.

21123034111 is a deficient number, since it is larger than the sum of its proper divisors (1).

21123034111 is an equidigital number, since it uses as much as digits as its factorization.

21123034111 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 19.

Adding to 21123034111 its reverse (11143032112), we get a palindrome (32266066223).

The spelling of 21123034111 in words is "twenty-one billion, one hundred twenty-three million, thirty-four thousand, one hundred eleven".