645434500643 has 4 divisors (see below), whose sum is σ = 645436233168. Its totient is φ = 645432768120.

The previous prime is 645434500631. The next prime is 645434500699. The reversal of 645434500643 is 346005434546.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 645434500643 - 2⁸ = 645434500387 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 645434500594 and 645434500603.

It is not an unprimeable number, because it can be changed into a prime (645434580643) 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 in 3 ways as a sum of consecutive naturals, for example, 52868 + ... + 1137393.

It is an arithmetic number, because the mean of its divisors is an integer number (161359058292).

Almost surely, 2^645434500643 is an apocalyptic number.

645434500643 is a deficient number, since it is larger than the sum of its proper divisors (1732525).

645434500643 is a wasteful number, since it uses less digits than its factorization.

645434500643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1732524.

The product of its (nonzero) digits is 2073600, while the sum is 44.

The spelling of 645434500643 in words is "six hundred forty-five billion, four hundred thirty-four million, five hundred thousand, six hundred forty-three".