123987 has 8 divisors (see below), whose sum is σ = 169936. Its totient is φ = 80352.

The previous prime is 123983. The next prime is 123989. The reversal of 123987 is 789321.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 123987 - 2² = 123983 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 123987.

It is not an unprimeable number, because it can be changed into a prime (123983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 448 + ... + 669.

It is an arithmetic number, because the mean of its divisors is an integer number (21242).

2¹²³⁹⁸⁷ is an apocalyptic number.

123987 is a deficient number, since it is larger than the sum of its proper divisors (45949).

123987 is a wasteful number, since it uses less digits than its factorization.

123987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1157.

The product of its digits is 3024, while the sum is 30.

The square root of 123987 is about 352.1178779897. The cubic root of 123987 is about 49.8645668216.

It can be divided in two parts, 1239 and 87, that added together give a triangular number (1326 = T₅₁).

The spelling of 123987 in words is "one hundred twenty-three thousand, nine hundred eighty-seven".