664610323421 has 24 divisors (see below), whose sum is σ = 754270927872. Its totient is φ = 584558805600.

The previous prime is 664610323417. The next prime is 664610323441. The reversal of 664610323421 is 124323016466.

It is not a de Polignac number, because 664610323421 - 2² = 664610323417 is a prime.

It is a super-2 number, since 2×664610323421² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664610323441) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17224076 + ... + 17262618.

It is an arithmetic number, because the mean of its divisors is an integer number (31427955328).

Almost surely, 2^664610323421 is an apocalyptic number.

It is an amenable number.

664610323421 is a deficient number, since it is larger than the sum of its proper divisors (89660604451).

664610323421 is a wasteful number, since it uses less digits than its factorization.

664610323421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43193 (or 43182 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 38.

Adding to 664610323421 its reverse (124323016466), we get a palindrome (788933339887).

The spelling of 664610323421 in words is "six hundred sixty-four billion, six hundred ten million, three hundred twenty-three thousand, four hundred twenty-one".