645606555929 has 2 divisors, whose sum is σ = 645606555930. Its totient is φ = 645606555928.

The previous prime is 645606555917. The next prime is 645606556079. The reversal of 645606555929 is 929555606546.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 608618419600 + 36988136329 = 780140^2 + 192323^2 .

It is a cyclic number.

It is not a de Polignac number, because 645606555929 - 2¹⁶ = 645606490393 is a prime.

It is not a weakly prime, because it can be changed into another prime (645606525929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322803277964 + 322803277965.

It is an arithmetic number, because the mean of its divisors is an integer number (322803277965).

Almost surely, 2^645606555929 is an apocalyptic number.

It is an amenable number.

645606555929 is a deficient number, since it is larger than the sum of its proper divisors (1).

645606555929 is an equidigital number, since it uses as much as digits as its factorization.

645606555929 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 87480000, while the sum is 62.

The spelling of 645606555929 in words is "six hundred forty-five billion, six hundred six million, five hundred fifty-five thousand, nine hundred twenty-nine".