65507440 has 80 divisors (see below), whose sum is σ = 162846720. Its totient is φ = 24433920.

The previous prime is 65507423. The next prime is 65507479. The reversal of 65507440 is 4470556.

It is a happy number.

65507440 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 (80).

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 15 ways as a sum of consecutive naturals, for example, 107617 + ... + 108223.

It is an arithmetic number, because the mean of its divisors is an integer number (2035584).

Almost surely, 2^65507440 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 65507440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81423360).

65507440 is an abundant number, since it is smaller than the sum of its proper divisors (97339280).

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

65507440 is a wasteful number, since it uses less digits than its factorization.

65507440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 710 (or 704 counting only the distinct ones).

The product of its (nonzero) digits is 16800, while the sum is 31.

The square root of 65507440 is about 8093.6666598026. Note that the first 4 decimals coincide. The cubic root of 65507440 is about 403.1161608141.

Adding to 65507440 its reverse (4470556), we get a palindrome (69977996).

The spelling of 65507440 in words is "sixty-five million, five hundred seven thousand, four hundred forty".