647172545 has 8 divisors (see below), whose sum is σ = 778294440. Its totient is φ = 516613120.

The previous prime is 647172529. The next prime is 647172557. The reversal of 647172545 is 545271746.

It can be written as a sum of positive squares in 4 ways, for example, as 6880129 + 640292416 = 2623^2 + 25304^2 .

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

It is not a de Polignac number, because 647172545 - 2⁴ = 647172529 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 138080 + ... + 142689.

It is an arithmetic number, because the mean of its divisors is an integer number (97286805).

Almost surely, 2^647172545 is an apocalyptic number.

It is an amenable number.

647172545 is a deficient number, since it is larger than the sum of its proper divisors (131121895).

647172545 is a wasteful number, since it uses less digits than its factorization.

647172545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281235.

The product of its digits is 235200, while the sum is 41.

The square root of 647172545 is about 25439.5861798104. The cubic root of 647172545 is about 864.9812530046.

The spelling of 647172545 in words is "six hundred forty-seven million, one hundred seventy-two thousand, five hundred forty-five".