645180671 has 2 divisors, whose sum is σ = 645180672. Its totient is φ = 645180670.

The previous prime is 645180647. The next prime is 645180737. The reversal of 645180671 is 176081546.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645180671 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645180611) 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, 322590335 + 322590336.

It is an arithmetic number, because the mean of its divisors is an integer number (322590336).

Almost surely, 2^645180671 is an apocalyptic number.

645180671 is a deficient number, since it is larger than the sum of its proper divisors (1).

645180671 is an equidigital number, since it uses as much as digits as its factorization.

645180671 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40320, while the sum is 38.

The square root of 645180671 is about 25400.4069061895. The cubic root of 645180671 is about 864.0929250869.

The spelling of 645180671 in words is "six hundred forty-five million, one hundred eighty thousand, six hundred seventy-one".