665382564 has 216 divisors, whose sum is σ = 2178042048. Its totient is φ = 169303680.

The previous prime is 665382551. The next prime is 665382611. The reversal of 665382564 is 465283566.

665382564 is a `hidden beast` number, since 6 + 6 + 5 + 3 + 82 + 564 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1028089 + ... + 1028735.

It is an arithmetic number, because the mean of its divisors is an integer number (10083528).

Almost surely, 2^665382564 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 665382564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1089021024).

665382564 is an abundant number, since it is smaller than the sum of its proper divisors (1512659484).

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

665382564 is a wasteful number, since it uses less digits than its factorization.

665382564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 735 (or 723 counting only the distinct ones).

The product of its digits is 1036800, while the sum is 45.

The square root of 665382564 is about 25795.0104477591. The cubic root of 665382564 is about 873.0192207323.

The spelling of 665382564 in words is "six hundred sixty-five million, three hundred eighty-two thousand, five hundred sixty-four".