645053687 has 2 divisors, whose sum is σ = 645053688. Its totient is φ = 645053686.

The previous prime is 645053683. The next prime is 645053741. The reversal of 645053687 is 786350546.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 645053687 - 2² = 645053683 is a prime.

It is a super-2 number, since 2×645053687² = 832188518224587938, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645053683) 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, 322526843 + 322526844.

It is an arithmetic number, because the mean of its divisors is an integer number (322526844).

Almost surely, 2^645053687 is an apocalyptic number.

645053687 is a deficient number, since it is larger than the sum of its proper divisors (1).

645053687 is an equidigital number, since it uses as much as digits as its factorization.

645053687 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 604800, while the sum is 44.

The square root of 645053687 is about 25397.9071381876. The cubic root of 645053687 is about 864.0362313160.

The spelling of 645053687 in words is "six hundred forty-five million, fifty-three thousand, six hundred eighty-seven".