647505321 has 4 divisors (see below), whose sum is σ = 863340432. Its totient is φ = 431670212.

The previous prime is 647505317. The next prime is 647505329. The reversal of 647505321 is 123505746.

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 647505321 - 2² = 647505317 is a prime.

It is not an unprimeable number, because it can be changed into a prime (647505329) 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, 107917551 + ... + 107917556.

It is an arithmetic number, because the mean of its divisors is an integer number (215835108).

Almost surely, 2^647505321 is an apocalyptic number.

It is an amenable number.

647505321 is a deficient number, since it is larger than the sum of its proper divisors (215835111).

647505321 is a wasteful number, since it uses less digits than its factorization.

647505321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215835110.

The product of its (nonzero) digits is 25200, while the sum is 33.

The square root of 647505321 is about 25446.1258544400. The cubic root of 647505321 is about 865.1294853326.

The spelling of 647505321 in words is "six hundred forty-seven million, five hundred five thousand, three hundred twenty-one".