645891052187 has 2 divisors, whose sum is σ = 645891052188. Its totient is φ = 645891052186.

The previous prime is 645891052127. The next prime is 645891052277. The reversal of 645891052187 is 781250198546.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 645891052187 - 2⁶ = 645891052123 is a prime.

It is not a weakly prime, because it can be changed into another prime (645891052127) 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, 322945526093 + 322945526094.

It is an arithmetic number, because the mean of its divisors is an integer number (322945526094).

Almost surely, 2^645891052187 is an apocalyptic number.

645891052187 is a deficient number, since it is larger than the sum of its proper divisors (1).

645891052187 is an equidigital number, since it uses as much as digits as its factorization.

645891052187 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4838400, while the sum is 56.

The spelling of 645891052187 in words is "six hundred forty-five billion, eight hundred ninety-one million, fifty-two thousand, one hundred eighty-seven".