123989555 has 4 divisors (see below), whose sum is σ = 148787472. Its totient is φ = 99191640.

The previous prime is 123989543. The next prime is 123989557. The reversal of 123989555 is 555989321.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 123989555 - 2⁴ = 123989539 is a prime.

It is a Duffinian number.

It is a plaindrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (123989557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12398951 + ... + 12398960.

It is an arithmetic number, because the mean of its divisors is an integer number (37196868).

Almost surely, 2^123989555 is an apocalyptic number.

123989555 is a deficient number, since it is larger than the sum of its proper divisors (24797917).

123989555 is an equidigital number, since it uses as much as digits as its factorization.

123989555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24797916.

The product of its digits is 486000, while the sum is 47.

The square root of 123989555 is about 11135.0597214384. The cubic root of 123989555 is about 498.6490933898.

The spelling of 123989555 in words is "one hundred twenty-three million, nine hundred eighty-nine thousand, five hundred fifty-five".