218634240 has 192 divisors, whose sum is σ = 764225280. Its totient is φ = 52920320.

The previous prime is 218634209. The next prime is 218634253. The reversal of 218634240 is 42436812.

It is a tau number, because it is divible by the number of its divisors (192).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 218634198 and 218634207.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 337597 + ... + 338243.

It is an arithmetic number, because the mean of its divisors is an integer number (3980340).

Almost surely, 2^218634240 is an apocalyptic number.

218634240 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 218634240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (382112640).

218634240 is an abundant number, since it is smaller than the sum of its proper divisors (545591040).

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

218634240 is a wasteful number, since it uses less digits than its factorization.

218634240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 688 (or 668 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 30.

The square root of 218634240 is about 14786.2855376190. The cubic root of 218634240 is about 602.4292623116.

The spelling of 218634240 in words is "two hundred eighteen million, six hundred thirty-four thousand, two hundred forty".