21231240121123 has 2 divisors, whose sum is σ = 21231240121124. Its totient is φ = 21231240121122.

The previous prime is 21231240121067. The next prime is 21231240121141. The reversal of 21231240121123 is 32112104213212.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21231240121123 is a prime.

It is a super-2 number, since 2×21231240121123² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21231240121183) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615620060561 + 10615620060562.

It is an arithmetic number, because the mean of its divisors is an integer number (10615620060562).

Almost surely, 2^{21231240121123} is an apocalyptic number.

21231240121123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231240121123 is an equidigital number, since it uses as much as digits as its factorization.

21231240121123 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 25.

Adding to 21231240121123 its reverse (32112104213212), we get a palindrome (53343344334335).

The spelling of 21231240121123 in words is "twenty-one trillion, two hundred thirty-one billion, two hundred forty million, one hundred twenty-one thousand, one hundred twenty-three".