221030640 has 80 divisors (see below), whose sum is σ = 761335200. Its totient is φ = 58940928.

The previous prime is 221030639. The next prime is 221030647. The reversal of 221030640 is 46030122.

It is a happy number.

221030640 is a `hidden beast` number, since 2 + 21 + 0 + 3 + 0 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (80).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221030647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49005 + ... + 53324.

It is an arithmetic number, because the mean of its divisors is an integer number (9516690).

Almost surely, 2^221030640 is an apocalyptic number.

221030640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221030640 is an abundant number, since it is smaller than the sum of its proper divisors (540304560).

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

221030640 is a wasteful number, since it uses less digits than its factorization.

221030640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102351 (or 102339 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 221030640 is about 14867.0992463224. The cubic root of 221030640 is about 604.6222991414.

Adding to 221030640 its reverse (46030122), we get a palindrome (267060762).

The spelling of 221030640 in words is "two hundred twenty-one million, thirty thousand, six hundred forty".