645785673 has 12 divisors (see below), whose sum is σ = 932377680. Its totient is φ = 397406256.

The previous prime is 645785671. The next prime is 645785677. The reversal of 645785673 is 376587546.

It is not a de Polignac number, because 645785673 - 2¹ = 645785671 is a prime.

It is not an unprimeable number, because it can be changed into a prime (645785671) 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, 636363 + ... + 637376.

It is an arithmetic number, because the mean of its divisors is an integer number (77698140).

Almost surely, 2^645785673 is an apocalyptic number.

It is an amenable number.

645785673 is a deficient number, since it is larger than the sum of its proper divisors (286592007).

645785673 is a wasteful number, since it uses less digits than its factorization.

645785673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1273768 (or 1273755 counting only the distinct ones).

The product of its digits is 4233600, while the sum is 51.

The square root of 645785673 is about 25412.3134129894. The cubic root of 645785673 is about 864.3629345324.

The spelling of 645785673 in words is "six hundred forty-five million, seven hundred eighty-five thousand, six hundred seventy-three".