65609984 has 72 divisors (see below), whose sum is σ = 149228352. Its totient is φ = 28497920.

The previous prime is 65609969. The next prime is 65609989. The reversal of 65609984 is 48990656.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65609989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 64262 + ... + 65274.

It is an arithmetic number, because the mean of its divisors is an integer number (2072616).

Almost surely, 2^65609984 is an apocalyptic number.

65609984 is a gapful number since it is divisible by the number (64) 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 65609984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74614176).

65609984 is an abundant number, since it is smaller than the sum of its proper divisors (83618368).

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

65609984 is a wasteful number, since it uses less digits than its factorization.

65609984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1063 (or 1049 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 47.

The square root of 65609984 is about 8099.9990123456. Note that the first 3 decimals coincide. The cubic root of 65609984 is about 403.3263944044.

The spelling of 65609984 in words is "sixty-five million, six hundred nine thousand, nine hundred eighty-four".