221530810 has 16 divisors (see below), whose sum is σ = 404708256. Its totient is φ = 87289488.

The previous prime is 221530801. The next prime is 221530919. The reversal of 221530810 is 18035122.

221530810 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×221530810² = 98151799558512200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 164652 + ... + 165991.

It is an arithmetic number, because the mean of its divisors is an integer number (25294266).

Almost surely, 2^221530810 is an apocalyptic number.

221530810 is a deficient number, since it is larger than the sum of its proper divisors (183177446).

221530810 is a wasteful number, since it uses less digits than its factorization.

221530810 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 330717.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 221530810 is about 14883.9111123387. The cubic root of 221530810 is about 605.0780219483.

Adding to 221530810 its reverse (18035122), we get a palindrome (239565932).

The spelling of 221530810 in words is "two hundred twenty-one million, five hundred thirty thousand, eight hundred ten".