21450544142281 has 2 divisors, whose sum is σ = 21450544142282. Its totient is φ = 21450544142280.

The previous prime is 21450544142221. The next prime is 21450544142303. The reversal of 21450544142281 is 18224144505412.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20638022182281 + 812521960000 = 4542909^2 + 901400^2 .

It is a cyclic number.

It is not a de Polignac number, because 21450544142281 - 2⁹ = 21450544141769 is a prime.

It is a super-2 number, since 2×21450544142281² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21450544142221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10725272071140 + 10725272071141.

It is an arithmetic number, because the mean of its divisors is an integer number (10725272071141).

Almost surely, 2^{21450544142281} is an apocalyptic number.

It is an amenable number.

21450544142281 is a deficient number, since it is larger than the sum of its proper divisors (1).

21450544142281 is an equidigital number, since it uses as much as digits as its factorization.

21450544142281 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 409600, while the sum is 43.

Adding to 21450544142281 its reverse (18224144505412), we get a palindrome (39674688647693).

The spelling of 21450544142281 in words is "twenty-one trillion, four hundred fifty billion, five hundred forty-four million, one hundred forty-two thousand, two hundred eighty-one".