123131221099 has 2 divisors, whose sum is σ = 123131221100. Its totient is φ = 123131221098.

The previous prime is 123131221079. The next prime is 123131221159. The reversal of 123131221099 is 990122131321.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 123131221099 - 2¹¹ = 123131219051 is a prime.

It is a super-2 number, since 2×123131221099² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (123131221019) 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, 61565610549 + 61565610550.

It is an arithmetic number, because the mean of its divisors is an integer number (61565610550).

Almost surely, 2^123131221099 is an apocalyptic number.

123131221099 is a deficient number, since it is larger than the sum of its proper divisors (1).

123131221099 is an equidigital number, since it uses as much as digits as its factorization.

123131221099 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5832, while the sum is 34.

The spelling of 123131221099 in words is "one hundred twenty-three billion, one hundred thirty-one million, two hundred twenty-one thousand, ninety-nine".