645542526032779 has 2 divisors, whose sum is σ = 645542526032780. Its totient is φ = 645542526032778.

The previous prime is 645542526032749. The next prime is 645542526032857. The reversal of 645542526032779 is 977230625245546.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 645542526032779 - 2¹⁵ = 645542526000011 is a prime.

It is not a weakly prime, because it can be changed into another prime (645542526032749) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322771263016389 + 322771263016390.

It is an arithmetic number, because the mean of its divisors is an integer number (322771263016390).

Almost surely, 2^{645542526032779} is an apocalyptic number.

645542526032779 is a deficient number, since it is larger than the sum of its proper divisors (1).

645542526032779 is an equidigital number, since it uses as much as digits as its factorization.

645542526032779 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 762048000, while the sum is 67.

The spelling of 645542526032779 in words is "six hundred forty-five trillion, five hundred forty-two billion, five hundred twenty-six million, thirty-two thousand, seven hundred seventy-nine".