21444532355555 has 4 divisors (see below), whose sum is σ = 25733438826672. Its totient is φ = 17155625884440.

The previous prime is 21444532355551. The next prime is 21444532355569. The reversal of 21444532355555 is 55555323544412.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21444532355555 - 2² = 21444532355551 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21444532355497 and 21444532355506.

It is not an unprimeable number, because it can be changed into a prime (21444532355551) 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 3 ways as a sum of consecutive naturals, for example, 2144453235551 + ... + 2144453235560.

It is an arithmetic number, because the mean of its divisors is an integer number (6433359706668).

Almost surely, 2^{21444532355555} is an apocalyptic number.

21444532355555 is a deficient number, since it is larger than the sum of its proper divisors (4288906471117).

21444532355555 is an equidigital number, since it uses as much as digits as its factorization.

21444532355555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4288906471116.

The product of its digits is 36000000, while the sum is 53.

Adding to 21444532355555 its reverse (55555323544412), we get a palindrome (76999855899967).

The spelling of 21444532355555 in words is "twenty-one trillion, four hundred forty-four billion, five hundred thirty-two million, three hundred fifty-five thousand, five hundred fifty-five".