645098899 has 2 divisors, whose sum is σ = 645098900. Its totient is φ = 645098898.

The previous prime is 645098893. The next prime is 645098921. The reversal of 645098899 is 998890546.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 645098899 - 2³ = 645098891 is a prime.

It is not a weakly prime, because it can be changed into another prime (645098891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322549449 + 322549450.

It is an arithmetic number, because the mean of its divisors is an integer number (322549450).

Almost surely, 2^645098899 is an apocalyptic number.

645098899 is a deficient number, since it is larger than the sum of its proper divisors (1).

645098899 is an equidigital number, since it uses as much as digits as its factorization.

645098899 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5598720, while the sum is 58.

The square root of 645098899 is about 25398.7971959304. The cubic root of 645098899 is about 864.0564176944.

The spelling of 645098899 in words is "six hundred forty-five million, ninety-eight thousand, eight hundred ninety-nine".