218493906 has 16 divisors (see below), whose sum is σ = 441315648. Its totient is φ = 72110000.

The previous prime is 218493881. The next prime is 218493907. The reversal of 218493906 is 609394812.

It is not an unprimeable number, because it can be changed into a prime (218493907) 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, 179670 + ... + 180881.

It is an arithmetic number, because the mean of its divisors is an integer number (27582228).

Almost surely, 2^218493906 is an apocalyptic number.

218493906 is an abundant number, since it is smaller than the sum of its proper divisors (222821742).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

218493906 is a wasteful number, since it uses less digits than its factorization.

218493906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360657.

The product of its (nonzero) digits is 93312, while the sum is 42.

The square root of 218493906 is about 14781.5393650323. The cubic root of 218493906 is about 602.3003416652.

The spelling of 218493906 in words is "two hundred eighteen million, four hundred ninety-three thousand, nine hundred six".