645731630369323 has 2 divisors, whose sum is σ = 645731630369324. Its totient is φ = 645731630369322.

The previous prime is 645731630369281. The next prime is 645731630369383. The reversal of 645731630369323 is 323963036137546.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 645731630369323 - 2²⁹ = 645731093498411 is a prime.

It is not a weakly prime, because it can be changed into another prime (645731630369383) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322865815184661 + 322865815184662.

It is an arithmetic number, because the mean of its divisors is an integer number (322865815184662).

Almost surely, 2^{645731630369323} is an apocalyptic number.

645731630369323 is a deficient number, since it is larger than the sum of its proper divisors (1).

645731630369323 is an equidigital number, since it uses as much as digits as its factorization.

645731630369323 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 132269760, while the sum is 61.

The spelling of 645731630369323 in words is "six hundred forty-five trillion, seven hundred thirty-one billion, six hundred thirty million, three hundred sixty-nine thousand, three hundred twenty-three".