645640607 has 2 divisors, whose sum is σ = 645640608. Its totient is φ = 645640606.

The previous prime is 645640591. The next prime is 645640643. The reversal of 645640607 is 706046546.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 645640607 - 2⁴ = 645640591 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645640507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322820303 + 322820304.

It is an arithmetic number, because the mean of its divisors is an integer number (322820304).

Almost surely, 2^645640607 is an apocalyptic number.

645640607 is a deficient number, since it is larger than the sum of its proper divisors (1).

645640607 is an equidigital number, since it uses as much as digits as its factorization.

645640607 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 120960, while the sum is 38.

The square root of 645640607 is about 25409.4590064409. The cubic root of 645640607 is about 864.2982076584.

The spelling of 645640607 in words is "six hundred forty-five million, six hundred forty thousand, six hundred seven".