20440312221 has 64 divisors (see below), whose sum is σ = 33621811200. Its totient is φ = 11018367360.

The previous prime is 20440312201. The next prime is 20440312223. The reversal of 20440312221 is 12221304402.

It is not a de Polignac number, because 20440312221 - 2¹¹ = 20440310173 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20440312223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1721776 + ... + 1733606.

It is an arithmetic number, because the mean of its divisors is an integer number (525340800).

Almost surely, 2^20440312221 is an apocalyptic number.

20440312221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20440312221 is a deficient number, since it is larger than the sum of its proper divisors (13181498979).

20440312221 is a wasteful number, since it uses less digits than its factorization.

20440312221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11951 (or 11937 counting only the distinct ones).

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

Adding to 20440312221 its reverse (12221304402), we get a palindrome (32661616623).

The spelling of 20440312221 in words is "twenty billion, four hundred forty million, three hundred twelve thousand, two hundred twenty-one".