218790400 has 60 divisors (see below), whose sum is σ = 542102022. Its totient is φ = 87511040.

The previous prime is 218790337. The next prime is 218790409. The reversal of 218790400 is 4097812.

It can be written as a sum of positive squares in 3 ways, for example, as 166719744 + 52070656 = 12912^2 + 7216^2 .

It is not an unprimeable number, because it can be changed into a prime (218790409) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4254 + ... + 21346.

Almost surely, 2^218790400 is an apocalyptic number.

218790400 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 218790400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (271051011).

218790400 is an abundant number, since it is smaller than the sum of its proper divisors (323311622).

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

218790400 is an equidigital number, since it uses as much as digits as its factorization.

218790400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17121 (or 17100 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 218790400 is about 14791.5651639710. The cubic root of 218790400 is about 602.5726569976.

The spelling of 218790400 in words is "two hundred eighteen million, seven hundred ninety thousand, four hundred".