645545207 has 2 divisors, whose sum is σ = 645545208. Its totient is φ = 645545206.

The previous prime is 645545189. The next prime is 645545269. The reversal of 645545207 is 702545546.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 645545207 - 2¹⁶ = 645479671 is a prime.

It is a super-2 number, since 2×645545207² = 833457228561345698, which contains 22 as substring.

It is equal to p_33573791 and since 645545207 and 33573791 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645547207) 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, 322772603 + 322772604.

It is an arithmetic number, because the mean of its divisors is an integer number (322772604).

Almost surely, 2^645545207 is an apocalyptic number.

645545207 is a deficient number, since it is larger than the sum of its proper divisors (1).

645545207 is an equidigital number, since it uses as much as digits as its factorization.

645545207 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 168000, while the sum is 38.

The square root of 645545207 is about 25407.5816834267. The cubic root of 645545207 is about 864.2556359296.

The spelling of 645545207 in words is "six hundred forty-five million, five hundred forty-five thousand, two hundred seven".