21024545281 has 2 divisors, whose sum is σ = 21024545282. Its totient is φ = 21024545280.

The previous prime is 21024545207. The next prime is 21024545401. The reversal of 21024545281 is 18254542012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16895840256 + 4128705025 = 129984^2 + 64255^2 .

It is a cyclic number.

It is not a de Polignac number, because 21024545281 - 2⁷ = 21024545153 is a prime.

It is a super-2 number, since 2×21024545281² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21024545081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10512272640 + 10512272641.

It is an arithmetic number, because the mean of its divisors is an integer number (10512272641).

Almost surely, 2^21024545281 is an apocalyptic number.

It is an amenable number.

21024545281 is a deficient number, since it is larger than the sum of its proper divisors (1).

21024545281 is an equidigital number, since it uses as much as digits as its factorization.

21024545281 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25600, while the sum is 34.

The spelling of 21024545281 in words is "twenty-one billion, twenty-four million, five hundred forty-five thousand, two hundred eighty-one".