645452332561 has 2 divisors, whose sum is σ = 645452332562. Its totient is φ = 645452332560.

The previous prime is 645452332549. The next prime is 645452332669. The reversal of 645452332561 is 165233254546.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 550332520336 + 95119812225 = 741844^2 + 308415^2 .

It is a cyclic number.

It is not a de Polignac number, because 645452332561 - 2⁵ = 645452332529 is a prime.

It is not a weakly prime, because it can be changed into another prime (645452332531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322726166280 + 322726166281.

It is an arithmetic number, because the mean of its divisors is an integer number (322726166281).

Almost surely, 2^645452332561 is an apocalyptic number.

It is an amenable number.

645452332561 is a deficient number, since it is larger than the sum of its proper divisors (1).

645452332561 is an equidigital number, since it uses as much as digits as its factorization.

645452332561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2592000, while the sum is 46.

The spelling of 645452332561 in words is "six hundred forty-five billion, four hundred fifty-two million, three hundred thirty-two thousand, five hundred sixty-one".