218945616 has 20 divisors (see below), whose sum is σ = 565609632. Its totient is φ = 72981856.

The previous prime is 218945609. The next prime is 218945663. The reversal of 218945616 is 616549812.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2280636 + ... + 2280731.

Almost surely, 2^218945616 is an apocalyptic number.

It is an amenable number.

218945616 is an abundant number, since it is smaller than the sum of its proper divisors (346664016).

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

218945616 is a wasteful number, since it uses less digits than its factorization.

218945616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4561378 (or 4561372 counting only the distinct ones).

The product of its digits is 103680, while the sum is 42.

The square root of 218945616 is about 14796.8110077814. The cubic root of 218945616 is about 602.7151172532.

The spelling of 218945616 in words is "two hundred eighteen million, nine hundred forty-five thousand, six hundred sixteen".