20421120440144 has 80 divisors (see below), whose sum is σ = 42696690250320. Its totient is φ = 9425765007360.

The previous prime is 20421120440131. The next prime is 20421120440167. The reversal of 20421120440144 is 44104402112402.

It can be written as a sum of positive squares in 8 ways, for example, as 2742627463744 + 17678492976400 = 1656088^2 + 4204580^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47778104 + ... + 48203624.

It is an arithmetic number, because the mean of its divisors is an integer number (533708628129).

Almost surely, 2^{20421120440144} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20421120440144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21348345125160).

20421120440144 is an abundant number, since it is smaller than the sum of its proper divisors (22275569810176).

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

20421120440144 is a wasteful number, since it uses less digits than its factorization.

20421120440144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 428928 (or 428922 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 29.

Adding to 20421120440144 its reverse (44104402112402), we get a palindrome (64525522552546).

The spelling of 20421120440144 in words is "twenty trillion, four hundred twenty-one billion, one hundred twenty million, four hundred forty thousand, one hundred forty-four".