21230123011 has 2 divisors, whose sum is σ = 21230123012. Its totient is φ = 21230123010.

The previous prime is 21230122909. The next prime is 21230123023. The reversal of 21230123011 is 11032103212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21230123011 - 2¹¹ = 21230120963 is a prime.

It is a super-2 number, since 2×21230123011² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21230123041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615061505 + 10615061506.

It is an arithmetic number, because the mean of its divisors is an integer number (10615061506).

Almost surely, 2^21230123011 is an apocalyptic number.

21230123011 is a deficient number, since it is larger than the sum of its proper divisors (1).

21230123011 is an equidigital number, since it uses as much as digits as its factorization.

21230123011 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21230123011 its reverse (11032103212), we get a palindrome (32262226223).

The spelling of 21230123011 in words is "twenty-one billion, two hundred thirty million, one hundred twenty-three thousand, eleven".