64665216 has 288 divisors, whose sum is σ = 240907680. Its totient is φ = 16796160.

The previous prime is 64665203. The next prime is 64665221. The reversal of 64665216 is 61256646.

It is a happy number.

64665216 is a `hidden beast` number, since 646 + 6 + 5 + 2 + 1 + 6 = 666.

64665216 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

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 35 ways as a sum of consecutive naturals, for example, 5878651 + ... + 5878661.

It is an arithmetic number, because the mean of its divisors is an integer number (836485).

Almost surely, 2^64665216 is an apocalyptic number.

64665216 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64665216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120453840).

64665216 is an abundant number, since it is smaller than the sum of its proper divisors (176242464).

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

64665216 is an frugal number, since it uses more digits than its factorization.

64665216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56 (or 23 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 64665216 is about 8041.4685226021. The cubic root of 64665216 is about 401.3810926363.

The spelling of 64665216 in words is "sixty-four million, six hundred sixty-five thousand, two hundred sixteen".