218306340 has 384 divisors, whose sum is σ = 846397440. Its totient is φ = 46189440.

The previous prime is 218306339. The next prime is 218306369. The reversal of 218306340 is 43603812.

It is a happy number.

218306340 is a `hidden beast` number, since 2 + 18 + 306 + 340 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 7042125 + ... + 7042155.

It is an arithmetic number, because the mean of its divisors is an integer number (2204160).

Almost surely, 2^218306340 is an apocalyptic number.

218306340 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 218306340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (423198720).

218306340 is an abundant number, since it is smaller than the sum of its proper divisors (628091100).

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

218306340 is a wasteful number, since it uses less digits than its factorization.

218306340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91 (or 71 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 218306340 is about 14775.1933997495. The cubic root of 218306340 is about 602.1279441675.

The spelling of 218306340 in words is "two hundred eighteen million, three hundred six thousand, three hundred forty".