21030554543281 has 2 divisors, whose sum is σ = 21030554543282. Its totient is φ = 21030554543280.

The previous prime is 21030554543279. The next prime is 21030554543353. The reversal of 21030554543281 is 18234545503012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17946737576881 + 3083816966400 = 4236359^2 + 1756080^2 .

It is a cyclic number.

It is not a de Polignac number, because 21030554543281 - 2¹ = 21030554543279 is a prime.

It is a super-2 number, since 2×21030554543281² (a number of 27 digits) contains 22 as substring.

Together with 21030554543279, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21030554543261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10515277271640 + 10515277271641.

It is an arithmetic number, because the mean of its divisors is an integer number (10515277271641).

Almost surely, 2^{21030554543281} is an apocalyptic number.

It is an amenable number.

21030554543281 is a deficient number, since it is larger than the sum of its proper divisors (1).

21030554543281 is an equidigital number, since it uses as much as digits as its factorization.

21030554543281 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576000, while the sum is 43.

The spelling of 21030554543281 in words is "twenty-one trillion, thirty billion, five hundred fifty-four million, five hundred forty-three thousand, two hundred eighty-one".