123155789 has 2 divisors, whose sum is σ = 123155790. Its totient is φ = 123155788.

The previous prime is 123155783. The next prime is 123155821. The reversal of 123155789 is 987551321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 94906564 + 28249225 = 9742^2 + 5315^2 .

It is an emirp because it is prime and its reverse (987551321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 123155789 - 2²⁰ = 122107213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123155783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61577894 + 61577895.

It is an arithmetic number, because the mean of its divisors is an integer number (61577895).

Almost surely, 2^123155789 is an apocalyptic number.

It is an amenable number.

123155789 is a deficient number, since it is larger than the sum of its proper divisors (1).

123155789 is an equidigital number, since it uses as much as digits as its factorization.

123155789 is an evil number, because the sum of its binary digits is even.

The product of its digits is 75600, while the sum is 41.

The square root of 123155789 is about 11097.5577943978. The cubic root of 123155789 is about 497.5288590449.

The spelling of 123155789 in words is "one hundred twenty-three million, one hundred fifty-five thousand, seven hundred eighty-nine".