20440745644891 has 16 divisors (see below), whose sum is σ = 25058402691840. Its totient is φ = 16407287471520.

The previous prime is 20440745644861. The next prime is 20440745644903. The reversal of 20440745644891 is 19844654704402.

It is not a de Polignac number, because 20440745644891 - 2⁵ = 20440745644859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20440745644861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3107437521 + ... + 3107444098.

It is an arithmetic number, because the mean of its divisors is an integer number (1566150168240).

Almost surely, 2^{20440745644891} is an apocalyptic number.

20440745644891 is a deficient number, since it is larger than the sum of its proper divisors (4617657046949).

20440745644891 is a wasteful number, since it uses less digits than its factorization.

20440745644891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6214881666.

The product of its (nonzero) digits is 30965760, while the sum is 58.

The spelling of 20440745644891 in words is "twenty trillion, four hundred forty billion, seven hundred forty-five million, six hundred forty-four thousand, eight hundred ninety-one".