665788968 has 96 divisors (see below), whose sum is σ = 1978671240. Its totient is φ = 200977920.

The previous prime is 665788919. The next prime is 665788979. The reversal of 665788968 is 869887566.

It can be written as a sum of positive squares in 4 ways, for example, as 638977284 + 26811684 = 25278^2 + 5178^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 42898 + ... + 56318.

Almost surely, 2^665788968 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 665788968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (989335620).

665788968 is an abundant number, since it is smaller than the sum of its proper divisors (1312882272).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

665788968 is a wasteful number, since it uses less digits than its factorization.

665788968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13499 (or 13492 counting only the distinct ones).

The product of its digits is 34836480, while the sum is 63.

The square root of 665788968 is about 25802.8868152383. The cubic root of 665788968 is about 873.1969261668.

The spelling of 665788968 in words is "six hundred sixty-five million, seven hundred eighty-eight thousand, nine hundred sixty-eight".