65181140640 has 1920 divisors, whose sum is σ = 309115699200. Its totient is φ = 12802406400.

The previous prime is 65181140623. The next prime is 65181140681. The reversal of 65181140640 is 4604118156.

65181140640 is a `hidden beast` number, since 6 + 5 + 1 + 8 + 1 + 1 + 4 + 0 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 65181140595 and 65181140604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 319 ways as a sum of consecutive naturals, for example, 1515840459 + ... + 1515840501.

It is an arithmetic number, because the mean of its divisors is an integer number (160997760).

Almost surely, 2^65181140640 is an apocalyptic number.

65181140640 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 65181140640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (154557849600).

65181140640 is an abundant number, since it is smaller than the sum of its proper divisors (243934558560).

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

65181140640 is a wasteful number, since it uses less digits than its factorization.

65181140640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133 (or 102 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

Adding to 65181140640 its reverse (4604118156), we get a palindrome (69785258796).

The spelling of 65181140640 in words is "sixty-five billion, one hundred eighty-one million, one hundred forty thousand, six hundred forty".