645441659 has 2 divisors, whose sum is σ = 645441660. Its totient is φ = 645441658.

The previous prime is 645441631. The next prime is 645441689. The reversal of 645441659 is 956144546.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 645441659 - 2⁸ = 645441403 is a prime.

It is not a weakly prime, because it can be changed into another prime (645441689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322720829 + 322720830.

It is an arithmetic number, because the mean of its divisors is an integer number (322720830).

Almost surely, 2^645441659 is an apocalyptic number.

645441659 is a deficient number, since it is larger than the sum of its proper divisors (1).

645441659 is an equidigital number, since it uses as much as digits as its factorization.

645441659 is an evil number, because the sum of its binary digits is even.

The product of its digits is 518400, while the sum is 44.

The square root of 645441659 is about 25405.5438634956. The cubic root of 645441659 is about 864.2094234532.

The spelling of 645441659 in words is "six hundred forty-five million, four hundred forty-one thousand, six hundred fifty-nine".