21544412220051 has 8 divisors (see below), whose sum is σ = 32829580525824. Its totient is φ = 12311092697160.

The previous prime is 21544412220049. The next prime is 21544412220077. The reversal of 21544412220051 is 15002221444512.

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

It is not a de Polignac number, because 21544412220051 - 2¹ = 21544412220049 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21544412219994 and 21544412220021.

It is not an unprimeable number, because it can be changed into a prime (21544412220041) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 512962195695 + ... + 512962195736.

It is an arithmetic number, because the mean of its divisors is an integer number (4103697565728).

Almost surely, 2^{21544412220051} is an apocalyptic number.

21544412220051 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21544412220051 is a deficient number, since it is larger than the sum of its proper divisors (11285168305773).

21544412220051 is a wasteful number, since it uses less digits than its factorization.

21544412220051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1025924391441.

The product of its (nonzero) digits is 25600, while the sum is 33.

Adding to 21544412220051 its reverse (15002221444512), we get a palindrome (36546633664563).

The spelling of 21544412220051 in words is "twenty-one trillion, five hundred forty-four billion, four hundred twelve million, two hundred twenty thousand, fifty-one".