645287189287 has 4 divisors (see below), whose sum is σ = 694924665400. Its totient is φ = 595649713176.

The previous prime is 645287189279. The next prime is 645287189297. The reversal of 645287189287 is 782981782546.

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 645287189287 - 2³ = 645287189279 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645287189207) 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, 24818738037 + ... + 24818738062.

It is an arithmetic number, because the mean of its divisors is an integer number (173731166350).

Almost surely, 2^645287189287 is an apocalyptic number.

645287189287 is a deficient number, since it is larger than the sum of its proper divisors (49637476113).

645287189287 is a wasteful number, since it uses less digits than its factorization.

645287189287 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49637476112.

The product of its digits is 108380160, while the sum is 67.

The spelling of 645287189287 in words is "six hundred forty-five billion, two hundred eighty-seven million, one hundred eighty-nine thousand, two hundred eighty-seven".