218400730 has 16 divisors (see below), whose sum is σ = 395161704. Its totient is φ = 86906880.

The previous prime is 218400719. The next prime is 218400731. The reversal of 218400730 is 37004812.

It can be written as a sum of positive squares in 4 ways, for example, as 187498249 + 30902481 = 13693^2 + 5559^2 .

It is a junction number, because it is equal to n+sod(n) for n = 218400695 and 218400704.

It is not an unprimeable number, because it can be changed into a prime (218400731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 54651 + ... + 58510.

Almost surely, 2^218400730 is an apocalyptic number.

218400730 is a deficient number, since it is larger than the sum of its proper divisors (176760974).

218400730 is a wasteful number, since it uses less digits than its factorization.

218400730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113361.

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 218400730 is about 14778.3872597791. The cubic root of 218400730 is about 602.2147131657.

The spelling of 218400730 in words is "two hundred eighteen million, four hundred thousand, seven hundred thirty".