218400740 has 48 divisors (see below), whose sum is σ = 482312880. Its totient is φ = 82951680.

The previous prime is 218400733. The next prime is 218400779. The reversal of 218400740 is 47004812.

It can be written as a sum of positive squares in 8 ways, for example, as 92467456 + 125933284 = 9616^2 + 11222^2 .

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, 32294 + ... + 38466.

It is an arithmetic number, because the mean of its divisors is an integer number (10048185).

Almost surely, 2^218400740 is an apocalyptic number.

218400740 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 218400740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (241156440).

218400740 is an abundant number, since it is smaller than the sum of its proper divisors (263912140).

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

218400740 is a wasteful number, since it uses less digits than its factorization.

218400740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6272 (or 6270 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 26.

The square root of 218400740 is about 14778.3875981110. The cubic root of 218400740 is about 602.2147223570.

The spelling of 218400740 in words is "two hundred eighteen million, four hundred thousand, seven hundred forty".