65681604 has 60 divisors (see below), whose sum is σ = 174119484. Its totient is φ = 21586176.

The previous prime is 65681599. The next prime is 65681611. The reversal of 65681604 is 40618656.

65681604 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 22752900 + 42928704 = 4770^2 + 6552^2 .

It is a super-4 number, since 4×65681604⁴ (a number of 32 digits) contains 4444 as substring.

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

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 19 ways as a sum of consecutive naturals, for example, 22264 + ... + 25040.

Almost surely, 2^65681604 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 65681604, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (87059742).

65681604 is an abundant number, since it is smaller than the sum of its proper divisors (108437880).

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

65681604 is a wasteful number, since it uses less digits than its factorization.

65681604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2866 (or 2855 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 65681604 is about 8104.4187947070. The cubic root of 65681604 is about 403.4730983571.

The spelling of 65681604 in words is "sixty-five million, six hundred eighty-one thousand, six hundred four".