311666 has 4 divisors (see below), whose sum is σ = 467502. Its totient is φ = 155832.

The previous prime is 311659. The next prime is 311677. The reversal of 311666 is 666113.

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

It can be written as a sum of positive squares in only one way, i.e., 297025 + 14641 = 545^2 + 121^2 .

It is an unprimeable number.

311666 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77915 + ... + 77918.

2³¹¹⁶⁶⁶ is an apocalyptic number.

311666 is a deficient number, since it is larger than the sum of its proper divisors (155836).

311666 is a wasteful number, since it uses less digits than its factorization.

311666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155835.

The product of its digits is 648, while the sum is 23.

The square root of 311666 is about 558.2705437331. The cubic root of 311666 is about 67.8000179834.

Adding to 311666 its reverse (666113), we get a palindrome (977779).

The spelling of 311666 in words is "three hundred eleven thousand, six hundred sixty-six".