16821023111 has 2 divisors, whose sum is σ = 16821023112. Its totient is φ = 16821023110.

The previous prime is 16821023077. The next prime is 16821023129. The reversal of 16821023111 is 11132012861.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 16821023111 - 2¹⁰ = 16821022087 is a prime.

It is a super-2 number, since 2×16821023111² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16821023161) 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, 8410511555 + 8410511556.

It is an arithmetic number, because the mean of its divisors is an integer number (8410511556).

Almost surely, 2^16821023111 is an apocalyptic number.

16821023111 is a deficient number, since it is larger than the sum of its proper divisors (1).

16821023111 is an equidigital number, since it uses as much as digits as its factorization.

16821023111 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 26.

Adding to 16821023111 its reverse (11132012861), we get a palindrome (27953035972).

The spelling of 16821023111 in words is "sixteen billion, eight hundred twenty-one million, twenty-three thousand, one hundred eleven".