645571617 has 8 divisors (see below), whose sum is σ = 911395296. Its totient is φ = 405064512.

The previous prime is 645571603. The next prime is 645571627. The reversal of 645571617 is 716175546.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 645571617 - 2¹⁰ = 645570593 is a prime.

It is not an unprimeable number, because it can be changed into a prime (645571627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6329083 + ... + 6329184.

It is an arithmetic number, because the mean of its divisors is an integer number (113924412).

Almost surely, 2^645571617 is an apocalyptic number.

It is an amenable number.

645571617 is a deficient number, since it is larger than the sum of its proper divisors (265823679).

645571617 is a wasteful number, since it uses less digits than its factorization.

645571617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12658287.

The product of its digits is 176400, while the sum is 42.

The square root of 645571617 is about 25408.1014048669. The cubic root of 645571617 is about 864.2674216677.

The spelling of 645571617 in words is "six hundred forty-five million, five hundred seventy-one thousand, six hundred seventeen".