645143123563 has 4 divisors (see below), whose sum is σ = 645162398440. Its totient is φ = 645123848688.

The previous prime is 645143123561. The next prime is 645143123591. The reversal of 645143123563 is 365321341546.

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 645143123563 - 2¹ = 645143123561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645143123561) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9587145 + ... + 9654202.

It is an arithmetic number, because the mean of its divisors is an integer number (161290599610).

Almost surely, 2^645143123563 is an apocalyptic number.

645143123563 is a deficient number, since it is larger than the sum of its proper divisors (19274877).

645143123563 is a wasteful number, since it uses less digits than its factorization.

645143123563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19274876.

The product of its digits is 777600, while the sum is 43.

The spelling of 645143123563 in words is "six hundred forty-five billion, one hundred forty-three million, one hundred twenty-three thousand, five hundred sixty-three".