221024640 has 64 divisors (see below), whose sum is σ = 704522160. Its totient is φ = 58939392.

The previous prime is 221024603. The next prime is 221024651. The reversal of 221024640 is 46420122.

221024640 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

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, 55639 + ... + 59478.

Almost surely, 2^221024640 is an apocalyptic number.

221024640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221024640 is an abundant number, since it is smaller than the sum of its proper divisors (483497520).

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

221024640 is a wasteful number, since it uses less digits than its factorization.

221024640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115139 (or 115127 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

The square root of 221024640 is about 14866.8974571025. The cubic root of 221024640 is about 604.6168281554.

Adding to 221024640 its reverse (46420122), we get a palindrome (267444762).

The spelling of 221024640 in words is "two hundred twenty-one million, twenty-four thousand, six hundred forty".