221431100 has 72 divisors (see below), whose sum is σ = 535465728. Its totient is φ = 78788800.

The previous prime is 221431061. The next prime is 221431127. The reversal of 221431100 is 1134122.

221431100 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

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, 49559 + ... + 53841.

It is an arithmetic number, because the mean of its divisors is an integer number (7437024).

Almost surely, 2^221431100 is an apocalyptic number.

221431100 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 221431100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (267732864).

221431100 is an abundant number, since it is smaller than the sum of its proper divisors (314034628).

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

221431100 is a wasteful number, since it uses less digits than its factorization.

221431100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4355 (or 4348 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 221431100 is about 14880.5611453332. The cubic root of 221431100 is about 604.9872273787.

Adding to 221431100 its reverse (1134122), we get a palindrome (222565222).

The spelling of 221431100 in words is "two hundred twenty-one million, four hundred thirty-one thousand, one hundred".