664635331121 has 16 divisors (see below), whose sum is σ = 695565711360. Its totient is φ = 634300450560.

The previous prime is 664635331037. The next prime is 664635331123. The reversal of 664635331121 is 121133536466.

It is a cyclic number.

It is not a de Polignac number, because 664635331121 - 2¹⁰ = 664635330097 is a prime.

It is a super-2 number, since 2×664635331121² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (664635331123) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23120285 + ... + 23149013.

It is an arithmetic number, because the mean of its divisors is an integer number (43472856960).

Almost surely, 2^664635331121 is an apocalyptic number.

It is an amenable number.

664635331121 is a deficient number, since it is larger than the sum of its proper divisors (30930380239).

664635331121 is a wasteful number, since it uses less digits than its factorization.

664635331121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39056.

The product of its digits is 233280, while the sum is 41.

Adding to 664635331121 its reverse (121133536466), we get a palindrome (785768867587).

The spelling of 664635331121 in words is "six hundred sixty-four billion, six hundred thirty-five million, three hundred thirty-one thousand, one hundred twenty-one".