218381478 has 64 divisors (see below), whose sum is σ = 527831040. Its totient is φ = 58840992.

The previous prime is 218381467. The next prime is 218381483. The reversal of 218381478 is 874183812.

It is a Harshad number since it is a multiple of its sum of digits (42).

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 polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 225351 + ... + 226317.

It is an arithmetic number, because the mean of its divisors is an integer number (8247360).

Almost surely, 2^218381478 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 218381478, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (263915520).

218381478 is an abundant number, since it is smaller than the sum of its proper divisors (309449562).

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

218381478 is a wasteful number, since it uses less digits than its factorization.

218381478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1281.

The product of its digits is 86016, while the sum is 42.

The square root of 218381478 is about 14777.7358888295. The cubic root of 218381478 is about 602.1970175925.

The spelling of 218381478 in words is "two hundred eighteen million, three hundred eighty-one thousand, four hundred seventy-eight".