220820644 has 18 divisors (see below), whose sum is σ = 424761302. Its totient is φ = 100372800.

The previous prime is 220820569. The next prime is 220820651. The reversal of 220820644 is 446028022.

It can be written as a sum of positive squares in only one way, i.e., 135443044 + 85377600 = 11638^2 + 9240^2 .

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 227637 + ... + 228604.

Almost surely, 2^220820644 is an apocalyptic number.

It is an amenable number.

220820644 is a deficient number, since it is larger than the sum of its proper divisors (203940658).

220820644 is a wasteful number, since it uses less digits than its factorization.

220820644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 456267 (or 456254 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 28.

The square root of 220820644 is about 14860.0351278185. The cubic root of 220820644 is about 604.4307593389.

Adding to 220820644 its reverse (446028022), we get a palindrome (666848666).

The spelling of 220820644 in words is "two hundred twenty million, eight hundred twenty thousand, six hundred forty-four".