65709440 has 64 divisors (see below), whose sum is σ = 159107760. Its totient is φ = 25946112.

The previous prime is 65709433. The next prime is 65709443. The reversal of 65709440 is 4490756.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×65709440² = 8635461010227200, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 65709440.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65709443) 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, 52502 + ... + 53738.

Almost surely, 2^65709440 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 65709440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79553880).

65709440 is an abundant number, since it is smaller than the sum of its proper divisors (93398320).

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

65709440 is a wasteful number, since it uses less digits than its factorization.

65709440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1339 (or 1327 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 35.

The square root of 65709440 is about 8106.1359475400. The cubic root of 65709440 is about 403.5300878858.

The spelling of 65709440 in words is "sixty-five million, seven hundred nine thousand, four hundred forty".