645332004281 has 2 divisors, whose sum is σ = 645332004282. Its totient is φ = 645332004280.

The previous prime is 645332004269. The next prime is 645332004341. The reversal of 645332004281 is 182400233546.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 575049222400 + 70282781881 = 758320^2 + 265109^2 .

It is a cyclic number.

It is not a de Polignac number, because 645332004281 - 2¹⁰ = 645332003257 is a prime.

It is a super-2 number, since 2×645332004281² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (645332004211) 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 as a sum of consecutive naturals, namely, 322666002140 + 322666002141.

It is an arithmetic number, because the mean of its divisors is an integer number (322666002141).

Almost surely, 2^645332004281 is an apocalyptic number.

It is an amenable number.

645332004281 is a deficient number, since it is larger than the sum of its proper divisors (1).

645332004281 is an equidigital number, since it uses as much as digits as its factorization.

645332004281 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 138240, while the sum is 38.

The spelling of 645332004281 in words is "six hundred forty-five billion, three hundred thirty-two million, four thousand, two hundred eighty-one".