239987 has 4 divisors (see below), whose sum is σ = 261816. Its totient is φ = 218160.

The previous prime is 239977. The next prime is 239999. The reversal of 239987 is 789932.

239987 is nontrivially palindromic in base 12.

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

It is a cyclic number.

It is not a de Polignac number, because 239987 - 2⁸ = 239731 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 239987.

It is not an unprimeable number, because it can be changed into a prime (239947) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10898 + ... + 10919.

It is an arithmetic number, because the mean of its divisors is an integer number (65454).

2²³⁹⁹⁸⁷ is an apocalyptic number.

239987 is a deficient number, since it is larger than the sum of its proper divisors (21829).

239987 is a wasteful number, since it uses less digits than its factorization.

239987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21828.

The product of its digits is 27216, while the sum is 38.

The square root of 239987 is about 489.8846803075. The cubic root of 239987 is about 62.1435280426.

Subtracting 239987 from its reverse (789932), we obtain a palindrome (549945).

The spelling of 239987 in words is "two hundred thirty-nine thousand, nine hundred eighty-seven".