664512222221 has 8 divisors (see below), whose sum is σ = 678440461824. Its totient is φ = 650635474320.

The previous prime is 664512222167. The next prime is 664512222251. The reversal of 664512222221 is 122222215466.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-664512222221 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 (664512222251) 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 7 ways as a sum of consecutive naturals, for example, 12846845 + ... + 12898466.

It is an arithmetic number, because the mean of its divisors is an integer number (84805057728).

Almost surely, 2^664512222221 is an apocalyptic number.

It is an amenable number.

664512222221 is a deficient number, since it is larger than the sum of its proper divisors (13928239603).

664512222221 is a wasteful number, since it uses less digits than its factorization.

664512222221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25745851.

The product of its digits is 46080, while the sum is 35.

Adding to 664512222221 its reverse (122222215466), we get a palindrome (786734437687).

The spelling of 664512222221 in words is "six hundred sixty-four billion, five hundred twelve million, two hundred twenty-two thousand, two hundred twenty-one".