221101800 has 192 divisors, whose sum is σ = 721828800. Its totient is φ = 55910400.

The previous prime is 221101799. The next prime is 221101801. The reversal of 221101800 is 8101122.

It is an interprime number because it is at equal distance from previous prime (221101799) and next prime (221101801).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 221101800.

It is not an unprimeable number, because it can be changed into a prime (221101801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1687735 + ... + 1687865.

It is an arithmetic number, because the mean of its divisors is an integer number (3759525).

Almost surely, 2^221101800 is an apocalyptic number.

221101800 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 221101800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (360914400).

221101800 is an abundant number, since it is smaller than the sum of its proper divisors (500727000).

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

221101800 is a wasteful number, since it uses less digits than its factorization.

221101800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276 (or 267 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

The square root of 221101800 is about 14869.4922576395. The cubic root of 221101800 is about 604.6871774865.

Adding to 221101800 its reverse (8101122), we get a palindrome (229202922).

The spelling of 221101800 in words is "two hundred twenty-one million, one hundred one thousand, eight hundred".