647663573 has 4 divisors (see below), whose sum is σ = 649498668. Its totient is φ = 645828480.

The previous prime is 647663561. The next prime is 647663579. The reversal of 647663573 is 375366746.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 317623684 + 330039889 = 17822^2 + 18167^2 .

It is a cyclic number.

It is not a de Polignac number, because 647663573 - 2¹² = 647659477 is a prime.

It is a super-2 number, since 2×647663573² = 838936207582252658, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647663579) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 917018 + ... + 917723.

It is an arithmetic number, because the mean of its divisors is an integer number (162374667).

Almost surely, 2^647663573 is an apocalyptic number.

It is an amenable number.

647663573 is a deficient number, since it is larger than the sum of its proper divisors (1835095).

647663573 is a wasteful number, since it uses less digits than its factorization.

647663573 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1835094.

The product of its digits is 1905120, while the sum is 47.

The square root of 647663573 is about 25449.2352144421. The cubic root of 647663573 is about 865.1999595638.

The spelling of 647663573 in words is "six hundred forty-seven million, six hundred sixty-three thousand, five hundred seventy-three".