218132491 has 8 divisors (see below), whose sum is σ = 231145920. Its totient is φ = 205139328.

The previous prime is 218132477. The next prime is 218132539. The reversal of 218132491 is 194231812.

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

It is a cyclic number.

It is not a de Polignac number, because 218132491 - 2⁷ = 218132363 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (218132441) 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, 20965 + ... + 29593.

It is an arithmetic number, because the mean of its divisors is an integer number (28893240).

Almost surely, 2^218132491 is an apocalyptic number.

218132491 is a deficient number, since it is larger than the sum of its proper divisors (13013429).

218132491 is a wasteful number, since it uses less digits than its factorization.

218132491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10133.

The product of its digits is 3456, while the sum is 31.

The square root of 218132491 is about 14769.3090901369. The cubic root of 218132491 is about 601.9680661714.

The spelling of 218132491 in words is "two hundred eighteen million, one hundred thirty-two thousand, four hundred ninety-one".