645603601 has 2 divisors, whose sum is σ = 645603602. Its totient is φ = 645603600.

The previous prime is 645603593. The next prime is 645603617. The reversal of 645603601 is 106306546.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 576048001 + 69555600 = 24001^2 + 8340^2 .

It is a cyclic number.

It is not a de Polignac number, because 645603601 - 2³ = 645603593 is a prime.

It is a zygodrome in base 3.

It is not a weakly prime, because it can be changed into another prime (645603001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322801800 + 322801801.

It is an arithmetic number, because the mean of its divisors is an integer number (322801801).

Almost surely, 2^645603601 is an apocalyptic number.

It is an amenable number.

645603601 is a deficient number, since it is larger than the sum of its proper divisors (1).

645603601 is an equidigital number, since it uses as much as digits as its factorization.

645603601 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 645603601 is about 25408.7308026198. The cubic root of 645603601 is about 864.2816944310.

The spelling of 645603601 in words is "six hundred forty-five million, six hundred three thousand, six hundred one".