65581920 has 384 divisors, whose sum is σ = 261273600. Its totient is φ = 15261696.

The previous prime is 65581907. The next prime is 65581961. The reversal of 65581920 is 2918556.

It is a happy number.

65581920 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 63 ways as a sum of consecutive naturals, for example, 1395337 + ... + 1395383.

It is an arithmetic number, because the mean of its divisors is an integer number (680400).

Almost surely, 2^65581920 is an apocalyptic number.

65581920 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 65581920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (130636800).

65581920 is an abundant number, since it is smaller than the sum of its proper divisors (195691680).

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

65581920 is a wasteful number, since it uses less digits than its factorization.

65581920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107 (or 93 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The square root of 65581920 is about 8098.2664811674. The cubic root of 65581920 is about 403.2688799557.

The spelling of 65581920 in words is "sixty-five million, five hundred eighty-one thousand, nine hundred twenty".