218933440 has 168 divisors, whose sum is σ = 598694256. Its totient is φ = 75571200.

The previous prime is 218933431. The next prime is 218933443. The reversal of 218933440 is 44339812.

It is a junction number, because it is equal to n+sod(n) for n = 218933396 and 218933405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218933443) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5339820 + ... + 5339860.

Almost surely, 2^218933440 is an apocalyptic number.

218933440 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 218933440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (299347128).

218933440 is an abundant number, since it is smaller than the sum of its proper divisors (379760816).

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

218933440 is a wasteful number, since it uses less digits than its factorization.

218933440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147 (or 96 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 34.

The square root of 218933440 is about 14796.3995620556. The cubic root of 218933440 is about 602.7039443184.

The spelling of 218933440 in words is "two hundred eighteen million, nine hundred thirty-three thousand, four hundred forty".