123989 has 2 divisors, whose sum is σ = 123990. Its totient is φ = 123988.

The previous prime is 123983. The next prime is 123997. The reversal of 123989 is 989321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 96100 + 27889 = 310^2 + 167^2 .

It is an emirp because it is prime and its reverse (989321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 123989 - 2⁴ = 123973 is a prime.

It is a Chen prime.

It is a plaindrome in base 13.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61994 + 61995.

It is an arithmetic number, because the mean of its divisors is an integer number (61995).

2¹²³⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

123989 is a deficient number, since it is larger than the sum of its proper divisors (1).

123989 is an equidigital number, since it uses as much as digits as its factorization.

123989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3888, while the sum is 32.

The square root of 123989 is about 352.1207179363. The cubic root of 123989 is about 49.8648349374.

The spelling of 123989 in words is "one hundred twenty-three thousand, nine hundred eighty-nine".