311697217 has 4 divisors (see below), whose sum is σ = 335673940. Its totient is φ = 287720496.

The previous prime is 311697203. The next prime is 311697257. The reversal of 311697217 is 712796113.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 712796113 = 31 ⋅22993423.

It can be written as a sum of positive squares in 2 ways, for example, as 99820081 + 211877136 = 9991^2 + 14556^2 .

It is a cyclic number.

It is not a de Polignac number, because 311697217 - 2¹⁵ = 311664449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (311697257) 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, 11988342 + ... + 11988367.

It is an arithmetic number, because the mean of its divisors is an integer number (83918485).

Almost surely, 2^311697217 is an apocalyptic number.

It is an amenable number.

311697217 is a deficient number, since it is larger than the sum of its proper divisors (23976723).

311697217 is a wasteful number, since it uses less digits than its factorization.

311697217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23976722.

The product of its digits is 15876, while the sum is 37.

The square root of 311697217 is about 17654.9487963007. The cubic root of 311697217 is about 678.0228156307.

The spelling of 311697217 in words is "three hundred eleven million, six hundred ninety-seven thousand, two hundred seventeen".