21440424321220 has 48 divisors (see below), whose sum is σ = 47679305084208. Its totient is φ = 8070691737600.

The previous prime is 21440424321167. The next prime is 21440424321259. The reversal of 21440424321220 is 2212342404412.

It can be written as a sum of positive squares in 8 ways, for example, as 8835780030016 + 12604644291204 = 2972504^2 + 3550302^2 .

It is an unprimeable number.

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, 1137777 + ... + 6646456.

It is an arithmetic number, because the mean of its divisors is an integer number (993318855921).

Almost surely, 2^{21440424321220} is an apocalyptic number.

21440424321220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21440424321220 is an abundant number, since it is smaller than the sum of its proper divisors (26238880762988).

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

21440424321220 is a wasteful number, since it uses less digits than its factorization.

21440424321220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7792360 (or 7792358 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 31.

Adding to 21440424321220 its reverse (2212342404412), we get a palindrome (23652766725632).

The spelling of 21440424321220 in words is "twenty-one trillion, four hundred forty billion, four hundred twenty-four million, three hundred twenty-one thousand, two hundred twenty".