391218117 has 8 divisors (see below), whose sum is σ = 522530496. Its totient is φ = 260358912.

The previous prime is 391218077. The next prime is 391218119. The reversal of 391218117 is 711812193.

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

It is not a de Polignac number, because 391218117 - 2¹⁰ = 391217093 is a prime.

It is a super-3 number, since 3×391218117³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391218119) 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, 111273 + ... + 114734.

It is an arithmetic number, because the mean of its divisors is an integer number (65316312).

Almost surely, 2^391218117 is an apocalyptic number.

It is an amenable number.

391218117 is a deficient number, since it is larger than the sum of its proper divisors (131312379).

391218117 is a wasteful number, since it uses less digits than its factorization.

391218117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226587.

The product of its digits is 3024, while the sum is 33.

The square root of 391218117 is about 19779.2344897370. The cubic root of 391218117 is about 731.3742281748.

The spelling of 391218117 in words is "three hundred ninety-one million, two hundred eighteen thousand, one hundred seventeen".