123420110557 has 2 divisors, whose sum is σ = 123420110558. Its totient is φ = 123420110556.

The previous prime is 123420110519. The next prime is 123420110563. The reversal of 123420110557 is 755011024321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 117723785881 + 5696324676 = 343109^2 + 75474^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123420110557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123420110257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61710055278 + 61710055279.

It is an arithmetic number, because the mean of its divisors is an integer number (61710055279).

Almost surely, 2^123420110557 is an apocalyptic number.

It is an amenable number.

123420110557 is a deficient number, since it is larger than the sum of its proper divisors (1).

123420110557 is an equidigital number, since it uses as much as digits as its factorization.

123420110557 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8400, while the sum is 31.

Adding to 123420110557 its reverse (755011024321), we get a palindrome (878431134878).

The spelling of 123420110557 in words is "one hundred twenty-three billion, four hundred twenty million, one hundred ten thousand, five hundred fifty-seven".