218189472 has 48 divisors (see below), whose sum is σ = 578676672. Its totient is φ = 71976960.

The previous prime is 218189471. The next prime is 218189473. The reversal of 218189472 is 274981812.

It is an interprime number because it is at equal distance from previous prime (218189471) and next prime (218189473).

It is a tau number, because it is divible by the number of its divisors (48).

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

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

It is not an unprimeable number, because it can be changed into a prime (218189471) 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, 2404 + ... + 21027.

It is an arithmetic number, because the mean of its divisors is an integer number (12055764).

Almost surely, 2^218189472 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 218189472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (289338336).

218189472 is an abundant number, since it is smaller than the sum of its proper divisors (360487200).

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

218189472 is a wasteful number, since it uses less digits than its factorization.

218189472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23541 (or 23533 counting only the distinct ones).

The product of its digits is 64512, while the sum is 42.

The square root of 218189472 is about 14771.2379982180. The cubic root of 218189472 is about 602.0204773703.

The spelling of 218189472 in words is "two hundred eighteen million, one hundred eighty-nine thousand, four hundred seventy-two".