221530504 has 16 divisors (see below), whose sum is σ = 447321420. Its totient is φ = 102244800.

The previous prime is 221530501. The next prime is 221530531. The reversal of 221530504 is 405035122.

It can be written as a sum of positive squares in 2 ways, for example, as 210308004 + 11222500 = 14502^2 + 3350^2 .

It is a super-3 number, since 3×221530504³ (a number of 26 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (221530501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1064947 + ... + 1065154.

Almost surely, 2^221530504 is an apocalyptic number.

It is an amenable number.

221530504 is an abundant number, since it is smaller than the sum of its proper divisors (225790916).

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

221530504 is a wasteful number, since it uses less digits than its factorization.

221530504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2130120 (or 2130116 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 221530504 is about 14883.9008327790. The cubic root of 221530504 is about 605.0777433505.

Adding to 221530504 its reverse (405035122), we get a palindrome (626565626).

The spelling of 221530504 in words is "two hundred twenty-one million, five hundred thirty thousand, five hundred four".