221530100 has 72 divisors (see below), whose sum is σ = 538694688. Its totient is φ = 78364800.

The previous prime is 221530097. The next prime is 221530103. The reversal of 221530100 is 1035122.

221530100 = T₁₇₆ + T₁₇₇ + ... + T₁₁₀₀.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (221530097) and next prime (221530103).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221530103) 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, 37979 + ... + 43421.

Almost surely, 2^221530100 is an apocalyptic number.

221530100 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 221530100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (269347344).

221530100 is an abundant number, since it is smaller than the sum of its proper divisors (317164588).

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

221530100 is a wasteful number, since it uses less digits than its factorization.

221530100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5505 (or 5498 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 14.

The square root of 221530100 is about 14883.8872610619. The cubic root of 221530100 is about 605.0773755282.

Adding to 221530100 its reverse (1035122), we get a palindrome (222565222).

The spelling of 221530100 in words is "two hundred twenty-one million, five hundred thirty thousand, one hundred".