647588993 has 8 divisors (see below), whose sum is σ = 659529960. Its totient is φ = 635690880.

The previous prime is 647588899. The next prime is 647589001. The reversal of 647588993 is 399885746.

It can be written as a sum of positive squares in 4 ways, for example, as 192321424 + 455267569 = 13868^2 + 21337^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 647588993 - 2²⁶ = 580480129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (647588093) 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, 20621 + ... + 41477.

It is an arithmetic number, because the mean of its divisors is an integer number (82441245).

Almost surely, 2^647588993 is an apocalyptic number.

It is an amenable number.

647588993 is a deficient number, since it is larger than the sum of its proper divisors (11940967).

647588993 is a wasteful number, since it uses less digits than its factorization.

647588993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21427.

The product of its digits is 13063680, while the sum is 59.

The square root of 647588993 is about 25447.7699022920. The cubic root of 647588993 is about 865.1667483450.

The spelling of 647588993 in words is "six hundred forty-seven million, five hundred eighty-eight thousand, nine hundred ninety-three".