664259616 has 120 divisors (see below), whose sum is σ = 2021162220. Its totient is φ = 213760512.

The previous prime is 664259611. The next prime is 664259647. The reversal of 664259616 is 616952466.

664259616 is a `hidden beast` number, since 6 + 6 + 4 + 25 + 9 + 616 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 566249616 + 98010000 = 23796^2 + 9900^2 .

It is a super-3 number, since 3×664259616³ (a number of 27 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (664259611) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 70750 + ... + 79586.

Almost surely, 2^664259616 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 664259616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1010581110).

664259616 is an abundant number, since it is smaller than the sum of its proper divisors (1356902604).

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

664259616 is a wasteful number, since it uses less digits than its factorization.

664259616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8888 (or 8871 counting only the distinct ones).

The product of its digits is 466560, while the sum is 45.

The square root of 664259616 is about 25773.2344885154. The cubic root of 664259616 is about 872.5278206141.

The spelling of 664259616 in words is "six hundred sixty-four million, two hundred fifty-nine thousand, six hundred sixteen".