645387937 has 2 divisors, whose sum is σ = 645387938. Its totient is φ = 645387936.

The previous prime is 645387931. The next prime is 645387971. The reversal of 645387937 is 739783546.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 636855696 + 8532241 = 25236^2 + 2921^2 .

It is a cyclic number.

It is not a de Polignac number, because 645387937 - 2¹¹ = 645385889 is a prime.

It is not a weakly prime, because it can be changed into another prime (645387931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322693968 + 322693969.

It is an arithmetic number, because the mean of its divisors is an integer number (322693969).

Almost surely, 2^645387937 is an apocalyptic number.

It is an amenable number.

645387937 is a deficient number, since it is larger than the sum of its proper divisors (1).

645387937 is an equidigital number, since it uses as much as digits as its factorization.

645387937 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3810240, while the sum is 52.

The square root of 645387937 is about 25404.4865525757. The cubic root of 645387937 is about 864.1854458940.

The spelling of 645387937 in words is "six hundred forty-five million, three hundred eighty-seven thousand, nine hundred thirty-seven".