218540400 has 120 divisors (see below), whose sum is σ = 753962160. Its totient is φ = 53790720.

The previous prime is 218540381. The next prime is 218540401. The reversal of 218540400 is 4045812.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218540401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8596 + ... + 22604.

It is an arithmetic number, because the mean of its divisors is an integer number (6283018).

Almost surely, 2^218540400 is an apocalyptic number.

218540400 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 218540400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (376981080).

218540400 is an abundant number, since it is smaller than the sum of its proper divisors (535421760).

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

218540400 is a wasteful number, since it uses less digits than its factorization.

218540400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14043 (or 14032 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 24.

The square root of 218540400 is about 14783.1119863174. Note that the first 3 decimals coincide. The cubic root of 218540400 is about 602.3430604249.

The spelling of 218540400 in words is "two hundred eighteen million, five hundred forty thousand, four hundred".