221210400 has 144 divisors (see below), whose sum is σ = 732328128. Its totient is φ = 57984000.

The previous prime is 221210387. The next prime is 221210413. The reversal of 221210400 is 4012122.

221210400 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (221210387) and next prime (221210413).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 145645 + ... + 147155.

It is an arithmetic number, because the mean of its divisors is an integer number (5085612).

Almost surely, 2^221210400 is an apocalyptic number.

221210400 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 221210400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (366164064).

221210400 is an abundant number, since it is smaller than the sum of its proper divisors (511117728).

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

221210400 is a wasteful number, since it uses less digits than its factorization.

221210400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1595 (or 1582 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 221210400 is about 14873.1435816373. The cubic root of 221210400 is about 604.7861639846.

Adding to 221210400 its reverse (4012122), we get a palindrome (225222522).

The spelling of 221210400 in words is "two hundred twenty-one million, two hundred ten thousand, four hundred".