311987 has 8 divisors (see below), whose sum is σ = 340704. Its totient is φ = 283968.

The previous prime is 311981. The next prime is 312007. The reversal of 311987 is 789113.

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

It is a cyclic number.

It is not a de Polignac number, because 311987 - 2¹² = 307891 is a prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 311987.

It is not an unprimeable number, because it can be changed into a prime (311981) 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, 1223 + ... + 1455.

It is an arithmetic number, because the mean of its divisors is an integer number (42588).

2³¹¹⁹⁸⁷ is an apocalyptic number.

311987 is a deficient number, since it is larger than the sum of its proper divisors (28717).

311987 is a wasteful number, since it uses less digits than its factorization.

311987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 349.

The product of its digits is 1512, while the sum is 29.

The square root of 311987 is about 558.5579647628. The cubic root of 311987 is about 67.8232868440.

The spelling of 311987 in words is "three hundred eleven thousand, nine hundred eighty-seven".