311861 has 4 divisors (see below), whose sum is σ = 340224. Its totient is φ = 283500.

The previous prime is 311827. The next prime is 311867. The reversal of 311861 is 168113.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-311861 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (311867) 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, 14165 + ... + 14186.

It is an arithmetic number, because the mean of its divisors is an integer number (85056).

2³¹¹⁸⁶¹ is an apocalyptic number.

It is an amenable number.

311861 is a deficient number, since it is larger than the sum of its proper divisors (28363).

311861 is a wasteful number, since it uses less digits than its factorization.

311861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28362.

The product of its digits is 144, while the sum is 20.

The square root of 311861 is about 558.4451629301. The cubic root of 311861 is about 67.8141551763.

Adding to 311861 its reverse (168113), we get a palindrome (479974).

The spelling of 311861 in words is "three hundred eleven thousand, eight hundred sixty-one".