664221356 has 6 divisors (see below), whose sum is σ = 1162387380. Its totient is φ = 332110676.

The previous prime is 664221293. The next prime is 664221359. The reversal of 664221356 is 653122466.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (664221359) 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 as a sum of consecutive naturals, namely, 83027666 + ... + 83027673.

It is an arithmetic number, because the mean of its divisors is an integer number (193731230).

Almost surely, 2^664221356 is an apocalyptic number.

It is an amenable number.

664221356 is a deficient number, since it is larger than the sum of its proper divisors (498166024).

664221356 is a wasteful number, since it uses less digits than its factorization.

664221356 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166055343 (or 166055341 counting only the distinct ones).

The product of its digits is 51840, while the sum is 35.

The square root of 664221356 is about 25772.4922349392. The cubic root of 664221356 is about 872.5110683511.

The spelling of 664221356 in words is "six hundred sixty-four million, two hundred twenty-one thousand, three hundred fifty-six".