645549122291 has 2 divisors, whose sum is σ = 645549122292. Its totient is φ = 645549122290.

The previous prime is 645549122237. The next prime is 645549122371. The reversal of 645549122291 is 192221945546.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 645549122291 - 2⁶ = 645549122227 is a prime.

It is not a weakly prime, because it can be changed into another prime (645549122221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322774561145 + 322774561146.

It is an arithmetic number, because the mean of its divisors is an integer number (322774561146).

Almost surely, 2^645549122291 is an apocalyptic number.

645549122291 is a deficient number, since it is larger than the sum of its proper divisors (1).

645549122291 is an equidigital number, since it uses as much as digits as its factorization.

645549122291 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1555200, while the sum is 50.

The spelling of 645549122291 in words is "six hundred forty-five billion, five hundred forty-nine million, one hundred twenty-two thousand, two hundred ninety-one".