65809680 has 80 divisors (see below), whose sum is σ = 209552064. Its totient is φ = 17072640.

The previous prime is 65809663. The next prime is 65809691. The reversal of 65809680 is 8690856.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5175 + ... + 12585.

Almost surely, 2^65809680 is an apocalyptic number.

65809680 is a gapful number since it is divisible by the number (60) 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 65809680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104776032).

65809680 is an abundant number, since it is smaller than the sum of its proper divisors (143742384).

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

65809680 is a wasteful number, since it uses less digits than its factorization.

65809680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7464 (or 7458 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 42.

The square root of 65809680 is about 8112.3165618706. The cubic root of 65809680 is about 403.7351791919.

The spelling of 65809680 in words is "sixty-five million, eight hundred nine thousand, six hundred eighty".