655005221 has 16 divisors (see below), whose sum is σ = 743467200. Its totient is φ = 572064768.

The previous prime is 655005203. The next prime is 655005269. The reversal of 655005221 is 122500556.

It is not a de Polignac number, because 655005221 - 2⁶ = 655005157 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 (655004221) 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 15 ways as a sum of consecutive naturals, for example, 299510 + ... + 301688.

It is an arithmetic number, because the mean of its divisors is an integer number (46466700).

Almost surely, 2^655005221 is an apocalyptic number.

It is an amenable number.

655005221 is a deficient number, since it is larger than the sum of its proper divisors (88461979).

655005221 is a wasteful number, since it uses less digits than its factorization.

655005221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3428.

The product of its (nonzero) digits is 3000, while the sum is 26.

The square root of 655005221 is about 25593.0697846116. The cubic root of 655005221 is about 868.4568677471.

Adding to 655005221 its reverse (122500556), we get a palindrome (777505777).

The spelling of 655005221 in words is "six hundred fifty-five million, five thousand, two hundred twenty-one".