645235544643 has 4 divisors (see below), whose sum is σ = 860314059528. Its totient is φ = 430157029760.

The previous prime is 645235544539. The next prime is 645235544647. The reversal of 645235544643 is 346445532546.

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 645235544643 - 2¹⁶ = 645235479107 is a prime.

It is not an unprimeable number, because it can be changed into a prime (645235544647) 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, 107539257438 + ... + 107539257443.

It is an arithmetic number, because the mean of its divisors is an integer number (215078514882).

Almost surely, 2^645235544643 is an apocalyptic number.

645235544643 is a deficient number, since it is larger than the sum of its proper divisors (215078514885).

645235544643 is a wasteful number, since it uses less digits than its factorization.

645235544643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215078514884.

The product of its digits is 20736000, while the sum is 51.

The spelling of 645235544643 in words is "six hundred forty-five billion, two hundred thirty-five million, five hundred forty-four thousand, six hundred forty-three".