645506672993 has 64 divisors (see below), whose sum is σ = 830986813440. Its totient is φ = 487723161600.

The previous prime is 645506672927. The next prime is 645506673011. The reversal of 645506672993 is 399276605546.

It is a cyclic number.

It is not a de Polignac number, because 645506672993 - 2¹² = 645506668897 is a prime.

It is not an unprimeable number, because it can be changed into a prime (645506674993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 98232398 + ... + 98238968.

It is an arithmetic number, because the mean of its divisors is an integer number (12984168960).

Almost surely, 2^645506672993 is an apocalyptic number.

It is an amenable number.

645506672993 is a deficient number, since it is larger than the sum of its proper divisors (185480140447).

645506672993 is a wasteful number, since it uses less digits than its factorization.

645506672993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7078.

The product of its (nonzero) digits is 73483200, while the sum is 62.

The spelling of 645506672993 in words is "six hundred forty-five billion, five hundred six million, six hundred seventy-two thousand, nine hundred ninety-three".