218427440 has 160 divisors (see below), whose sum is σ = 644958720. Its totient is φ = 66816000.

The previous prime is 218427367. The next prime is 218427497. The reversal of 218427440 is 44724812.

It is a junction number, because it is equal to n+sod(n) for n = 218427397 and 218427406.

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, 363140 + ... + 363740.

It is an arithmetic number, because the mean of its divisors is an integer number (4030992).

Almost surely, 2^218427440 is an apocalyptic number.

218427440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 218427440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (322479360).

218427440 is an abundant number, since it is smaller than the sum of its proper divisors (426531280).

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

218427440 is a wasteful number, since it uses less digits than its factorization.

218427440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 691 (or 685 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 32.

The square root of 218427440 is about 14779.2909166847. The cubic root of 218427440 is about 602.2392620753.

The spelling of 218427440 in words is "two hundred eighteen million, four hundred twenty-seven thousand, four hundred forty".