665646336 has 180 divisors, whose sum is σ = 2030035392. Its totient is φ = 216843264.

The previous prime is 665646329. The next prime is 665646341. The reversal of 665646336 is 633646566.

It is a happy number.

665646336 is a `hidden beast` number, since 6 + 6 + 5 + 6 + 4 + 633 + 6 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 665646291 and 665646300.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 974251 + ... + 974933.

Almost surely, 2^665646336 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 665646336, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1015017696).

665646336 is an abundant number, since it is smaller than the sum of its proper divisors (1364389056).

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

665646336 is an equidigital number, since it uses as much as digits as its factorization.

665646336 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 758 (or 735 counting only the distinct ones).

The product of its digits is 1399680, while the sum is 45.

The square root of 665646336 is about 25800.1227904055. The cubic root of 665646336 is about 873.1345667082.

It can be divided in two parts, 66564 and 6336, that added together give a square (72900 = 270²).

The spelling of 665646336 in words is "six hundred sixty-five million, six hundred forty-six thousand, three hundred thirty-six".