645798990043 has 2 divisors, whose sum is σ = 645798990044. Its totient is φ = 645798990042.

The previous prime is 645798990037. The next prime is 645798990049. The reversal of 645798990043 is 340099897546.

It is a balanced prime because it is at equal distance from previous prime (645798990037) and next prime (645798990049).

It is a cyclic number.

It is not a de Polignac number, because 645798990043 - 2²⁵ = 645765435611 is a prime.

It is not a weakly prime, because it can be changed into another prime (645798990049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322899495021 + 322899495022.

It is an arithmetic number, because the mean of its divisors is an integer number (322899495022).

Almost surely, 2^645798990043 is an apocalyptic number.

645798990043 is a deficient number, since it is larger than the sum of its proper divisors (1).

645798990043 is an equidigital number, since it uses as much as digits as its factorization.

645798990043 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 58786560, while the sum is 64.

It can be divided in two parts, 645798 and 990043, that added together give a square (1635841 = 1279²).

The spelling of 645798990043 in words is "six hundred forty-five billion, seven hundred ninety-eight million, nine hundred ninety thousand, forty-three".