647393321 has 4 divisors (see below), whose sum is σ = 663183444. Its totient is φ = 631603200.

The previous prime is 647393317. The next prime is 647393339. The reversal of 647393321 is 123393746.

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 24641296 + 622752025 = 4964^2 + 24955^2 .

It is a cyclic number.

It is not a de Polignac number, because 647393321 - 2² = 647393317 is a prime.

It is a super-2 number, since 2×647393321² = 838236224150818082, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (647393381) 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 3 ways as a sum of consecutive naturals, for example, 7895000 + ... + 7895081.

It is an arithmetic number, because the mean of its divisors is an integer number (165795861).

Almost surely, 2^647393321 is an apocalyptic number.

It is an amenable number.

647393321 is a deficient number, since it is larger than the sum of its proper divisors (15790123).

647393321 is a wasteful number, since it uses less digits than its factorization.

647393321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15790122.

The product of its digits is 81648, while the sum is 38.

The square root of 647393321 is about 25443.9250313312. The cubic root of 647393321 is about 865.0796015265.

The spelling of 647393321 in words is "six hundred forty-seven million, three hundred ninety-three thousand, three hundred twenty-one".