218916397 has 8 divisors (see below), whose sum is σ = 256008896. Its totient is φ = 183278592.

The previous prime is 218916349. The next prime is 218916407. The reversal of 218916397 is 793619812.

It is a happy number.

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

It is a de Polignac number, because none of the positive numbers 2^k-218916397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218916317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 363348 + ... + 363949.

It is an arithmetic number, because the mean of its divisors is an integer number (32001112).

Almost surely, 2^218916397 is an apocalyptic number.

It is an amenable number.

218916397 is a deficient number, since it is larger than the sum of its proper divisors (37092499).

218916397 is an equidigital number, since it uses as much as digits as its factorization.

218916397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 727347.

The product of its digits is 163296, while the sum is 46.

The square root of 218916397 is about 14795.8236337150. The cubic root of 218916397 is about 602.6883046337.

The spelling of 218916397 in words is "two hundred eighteen million, nine hundred sixteen thousand, three hundred ninety-seven".