20440628785 has 8 divisors (see below), whose sum is σ = 24532555176. Its totient is φ = 16349969280.

The previous prime is 20440628783. The next prime is 20440628837. The reversal of 20440628785 is 58782604402.

It can be written as a sum of positive squares in 4 ways, for example, as 1531078641 + 18909550144 = 39129^2 + 137512^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20440628785 - 2¹ = 20440628783 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20440628783) 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 7 ways as a sum of consecutive naturals, for example, 280854 + ... + 346063.

It is an arithmetic number, because the mean of its divisors is an integer number (3066569397).

Almost surely, 2^20440628785 is an apocalyptic number.

It is an amenable number.

20440628785 is a deficient number, since it is larger than the sum of its proper divisors (4091926391).

20440628785 is an equidigital number, since it uses as much as digits as its factorization.

20440628785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 633443.

The product of its (nonzero) digits is 860160, while the sum is 46.

The spelling of 20440628785 in words is "twenty billion, four hundred forty million, six hundred twenty-eight thousand, seven hundred eighty-five".