647412221 has 4 divisors (see below), whose sum is σ = 647497152. Its totient is φ = 647327292.

The previous prime is 647412217. The next prime is 647412247. The reversal of 647412221 is 122214746.

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 647412221 - 2² = 647412217 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 (647412281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29765 + ... + 46698.

It is an arithmetic number, because the mean of its divisors is an integer number (161874288).

Almost surely, 2^647412221 is an apocalyptic number.

It is an amenable number.

647412221 is a deficient number, since it is larger than the sum of its proper divisors (84931).

647412221 is an equidigital number, since it uses as much as digits as its factorization.

647412221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84930.

The product of its digits is 5376, while the sum is 29.

The square root of 647412221 is about 25444.2964335821. The cubic root of 647412221 is about 865.0880198223.

Adding to 647412221 its reverse (122214746), we get a palindrome (769626967).

The spelling of 647412221 in words is "six hundred forty-seven million, four hundred twelve thousand, two hundred twenty-one".