640570529 has 8 divisors (see below), whose sum is σ = 660622248. Its totient is φ = 620663040.

The previous prime is 640570517. The next prime is 640570549. The reversal of 640570529 is 925075046.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 321126400 + 319444129 = 17920^2 + 17873^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640570529 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 640570492 and 640570501.

It is not an unprimeable number, because it can be changed into a prime (640570549) 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, 27002 + ... + 44835.

It is an arithmetic number, because the mean of its divisors is an integer number (82577781).

Almost surely, 2^640570529 is an apocalyptic number.

It is an amenable number.

640570529 is a deficient number, since it is larger than the sum of its proper divisors (20051719).

640570529 is a wasteful number, since it uses less digits than its factorization.

640570529 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72115.

The product of its (nonzero) digits is 75600, while the sum is 38.

The square root of 640570529 is about 25309.4948388940. The cubic root of 640570529 is about 862.0298765132.

The spelling of 640570529 in words is "six hundred forty million, five hundred seventy thousand, five hundred twenty-nine".