21440520455321 has 8 divisors (see below), whose sum is σ = 23453390722944. Its totient is φ = 19438272195120.

The previous prime is 21440520455309. The next prime is 21440520455339. The reversal of 21440520455321 is 12355402504412.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21440520455321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21440520455371) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2655497630 + ... + 2655505703.

It is an arithmetic number, because the mean of its divisors is an integer number (2931673840368).

Almost surely, 2^{21440520455321} is an apocalyptic number.

It is an amenable number.

21440520455321 is a deficient number, since it is larger than the sum of its proper divisors (2012870267623).

21440520455321 is a wasteful number, since it uses less digits than its factorization.

21440520455321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5311003711.

The product of its (nonzero) digits is 192000, while the sum is 38.

Adding to 21440520455321 its reverse (12355402504412), we get a palindrome (33795922959733).

The spelling of 21440520455321 in words is "twenty-one trillion, four hundred forty billion, five hundred twenty million, four hundred fifty-five thousand, three hundred twenty-one".