664641123 has 8 divisors (see below), whose sum is σ = 888421968. Its totient is φ = 441977184.

The previous prime is 664641113. The next prime is 664641137. The reversal of 664641123 is 321146466.

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

It is not a de Polignac number, because 664641123 - 2⁹ = 664640611 is a prime.

It is a super-2 number, since 2×664641123² = 883495644765402258, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (664641113) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 277836 + ... + 280217.

It is an arithmetic number, because the mean of its divisors is an integer number (111052746).

Almost surely, 2^664641123 is an apocalyptic number.

664641123 is a deficient number, since it is larger than the sum of its proper divisors (223780845).

664641123 is a wasteful number, since it uses less digits than its factorization.

664641123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 558453.

The product of its digits is 20736, while the sum is 33.

The square root of 664641123 is about 25780.6346508382. The cubic root of 664641123 is about 872.6948294945.

Adding to 664641123 its reverse (321146466), we get a palindrome (985787589).

The spelling of 664641123 in words is "six hundred sixty-four million, six hundred forty-one thousand, one hundred twenty-three".