21444100220537 has 2 divisors, whose sum is σ = 21444100220538. Its totient is φ = 21444100220536.

The previous prime is 21444100220449. The next prime is 21444100220551. The reversal of 21444100220537 is 73502200144412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16316461524496 + 5127638696041 = 4039364^2 + 2264429^2 .

It is a cyclic number.

It is not a de Polignac number, because 21444100220537 - 2¹⁶ = 21444100155001 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21444100220497 and 21444100220506.

It is not a weakly prime, because it can be changed into another prime (21444100220437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10722050110268 + 10722050110269.

It is an arithmetic number, because the mean of its divisors is an integer number (10722050110269).

Almost surely, 2^{21444100220537} is an apocalyptic number.

It is an amenable number.

21444100220537 is a deficient number, since it is larger than the sum of its proper divisors (1).

21444100220537 is an equidigital number, since it uses as much as digits as its factorization.

21444100220537 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 53760, while the sum is 35.

Adding to 21444100220537 its reverse (73502200144412), we get a palindrome (94946300364949).

The spelling of 21444100220537 in words is "twenty-one trillion, four hundred forty-four billion, one hundred million, two hundred twenty thousand, five hundred thirty-seven".