647424221 has 16 divisors (see below), whose sum is σ = 695952000. Its totient is φ = 600465600.

The previous prime is 647424191. The next prime is 647424289. The reversal of 647424221 is 122424746.

It is a cyclic number.

It is not a de Polignac number, because 647424221 - 2¹⁴ = 647407837 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 (647421221) 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 15 ways as a sum of consecutive naturals, for example, 199391 + ... + 202611.

It is an arithmetic number, because the mean of its divisors is an integer number (43497000).

Almost surely, 2^647424221 is an apocalyptic number.

It is an amenable number.

647424221 is a deficient number, since it is larger than the sum of its proper divisors (48527779).

647424221 is a wasteful number, since it uses less digits than its factorization.

647424221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3460.

The product of its digits is 21504, while the sum is 32.

The square root of 647424221 is about 25444.5322417214. The cubic root of 647424221 is about 865.0933646869.

Adding to 647424221 its reverse (122424746), we get a palindrome (769848967).

The spelling of 647424221 in words is "six hundred forty-seven million, four hundred twenty-four thousand, two hundred twenty-one".