221400 has 96 divisors (see below), whose sum is σ = 781200. Its totient is φ = 57600.

The previous prime is 221399. The next prime is 221401. The reversal of 221400 is 4122.

It is an interprime number because it is at equal distance from previous prime (221399) and next prime (221401).

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 221400.

It is not an unprimeable number, because it can be changed into a prime (221401) 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, 5380 + ... + 5420.

2²²¹⁴⁰⁰ is an apocalyptic number.

221400 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 221400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (390600).

221400 is an abundant number, since it is smaller than the sum of its proper divisors (559800).

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

221400 is a wasteful number, since it uses less digits than its factorization.

221400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66 (or 51 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 9.

The square root of 221400 is about 470.5316142407. The cubic root of 221400 is about 60.4958902565.

Adding to 221400 its reverse (4122), we get a palindrome (225522).

The spelling of 221400 in words is "two hundred twenty-one thousand, four hundred", and thus it is an iban number.