65118640 has 40 divisors (see below), whose sum is σ = 153673200. Its totient is φ = 25656576.

The previous prime is 65118637. The next prime is 65118649. The reversal of 65118640 is 4681156.

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (65118649) 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, 715 + ... + 11434.

It is an arithmetic number, because the mean of its divisors is an integer number (3841830).

Almost surely, 2^65118640 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 65118640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76836600).

65118640 is an abundant number, since it is smaller than the sum of its proper divisors (88554560).

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

65118640 is a wasteful number, since it uses less digits than its factorization.

65118640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12229 (or 12223 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 65118640 is about 8069.6121344213. The cubic root of 65118640 is about 402.3170522562.

Adding to 65118640 its reverse (4681156), we get a palindrome (69799796).

It can be divided in two parts, 6511 and 8640, that added together give a palindrome (15151).

The spelling of 65118640 in words is "sixty-five million, one hundred eighteen thousand, six hundred forty".