305987 has 4 divisors (see below), whose sum is σ = 333816. Its totient is φ = 278160.

The previous prime is 305971. The next prime is 305999. The reversal of 305987 is 789503.

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 305987 - 2⁴ = 305971 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 305987.

It is not an unprimeable number, because it can be changed into a prime (305917) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13898 + ... + 13919.

It is an arithmetic number, because the mean of its divisors is an integer number (83454).

2³⁰⁵⁹⁸⁷ is an apocalyptic number.

305987 is a deficient number, since it is larger than the sum of its proper divisors (27829).

305987 is a wasteful number, since it uses less digits than its factorization.

305987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27828.

The product of its (nonzero) digits is 7560, while the sum is 32.

The square root of 305987 is about 553.1609169130. The cubic root of 305987 is about 67.3856867175.

The spelling of 305987 in words is "three hundred five thousand, nine hundred eighty-seven".