221345100 has 324 divisors, whose sum is σ = 789834864. Its totient is φ = 51701760.

The previous prime is 221345093. The next prime is 221345141. The reversal of 221345100 is 1543122.

221345100 is a `hidden beast` number, since 2 + 213 + 451 + 0 + 0 = 666.

221345100 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 5982282 + ... + 5982318.

Almost surely, 2^221345100 is an apocalyptic number.

221345100 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 221345100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (394917432).

221345100 is an abundant number, since it is smaller than the sum of its proper divisors (568489764).

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

221345100 is a wasteful number, since it uses less digits than its factorization.

221345100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114 (or 87 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 221345100 is about 14877.6711887311. The cubic root of 221345100 is about 604.9088950537.

Adding to 221345100 its reverse (1543122), we get a palindrome (222888222).

It can be divided in two parts, 221345 and 100, that added together give a triangular number (221445 = T₆₆₅).

The spelling of 221345100 in words is "two hundred twenty-one million, three hundred forty-five thousand, one hundred".