665996064 has 72 divisors (see below), whose sum is σ = 1806703920. Its totient is φ = 214807680.

The previous prime is 665996057. The next prime is 665996077. The reversal of 665996064 is 460699566.

It is a super-3 number, since 3×665996064³ (a number of 27 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 665995998 and 665996016.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 88647 + ... + 95865.

It is an arithmetic number, because the mean of its divisors is an integer number (25093110).

Almost surely, 2^665996064 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 665996064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (903351960).

665996064 is an abundant number, since it is smaller than the sum of its proper divisors (1140707856).

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

665996064 is a wasteful number, since it uses less digits than its factorization.

665996064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7294 (or 7255 counting only the distinct ones).

The product of its (nonzero) digits is 2099520, while the sum is 51.

The square root of 665996064 is about 25806.8995425642. The cubic root of 665996064 is about 873.2874537728.

The spelling of 665996064 in words is "six hundred sixty-five million, nine hundred ninety-six thousand, sixty-four".