645499782729 has 12 divisors (see below), whose sum is σ = 936289785600. Its totient is φ = 428532629784.

The previous prime is 645499782709. The next prime is 645499782751. The reversal of 645499782729 is 927287994546.

645499782729 is a `hidden beast` number, since 6 + 4 + 549 + 9 + 7 + 8 + 2 + 72 + 9 = 666.

It is not a de Polignac number, because 645499782729 - 2⁷ = 645499782601 is a prime.

It is not an unprimeable number, because it can be changed into a prime (645499782709) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 150044289 + ... + 150048590.

It is an arithmetic number, because the mean of its divisors is an integer number (78024148800).

Almost surely, 2^645499782729 is an apocalyptic number.

It is an amenable number.

645499782729 is a deficient number, since it is larger than the sum of its proper divisors (290790002871).

645499782729 is a wasteful number, since it uses less digits than its factorization.

645499782729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 300093124 (or 300093121 counting only the distinct ones).

The product of its digits is 548674560, while the sum is 72.

The spelling of 645499782729 in words is "six hundred forty-five billion, four hundred ninety-nine million, seven hundred eighty-two thousand, seven hundred twenty-nine".