647665573 has 4 divisors (see below), whose sum is σ = 648964000. Its totient is φ = 646367148.

The previous prime is 647665537. The next prime is 647665607. The reversal of 647665573 is 375566746.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 647665573 - 2⁹ = 647665061 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647665273) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 648465 + ... + 649462.

It is an arithmetic number, because the mean of its divisors is an integer number (162241000).

Almost surely, 2^647665573 is an apocalyptic number.

It is an amenable number.

647665573 is a deficient number, since it is larger than the sum of its proper divisors (1298427).

647665573 is a wasteful number, since it uses less digits than its factorization.

647665573 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1298426.

The product of its digits is 3175200, while the sum is 49.

The square root of 647665573 is about 25449.2745083234. The cubic root of 647665573 is about 865.2008501487.

The spelling of 647665573 in words is "six hundred forty-seven million, six hundred sixty-five thousand, five hundred seventy-three".