65640490578264 has 256 divisors, whose sum is σ = 206133903360000. Its totient is φ = 17360336568960.

The previous prime is 65640490578217. The next prime is 65640490578277. The reversal of 65640490578264 is 46287509404656.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 65640490578195 and 65640490578204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 277677 + ... + 11461155.

It is an arithmetic number, because the mean of its divisors is an integer number (805210560000).

Almost surely, 2^{65640490578264} 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 65640490578264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103066951680000).

65640490578264 is an abundant number, since it is smaller than the sum of its proper divisors (140493412781736).

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

65640490578264 is a wasteful number, since it uses less digits than its factorization.

65640490578264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11183563 (or 11183545 counting only the distinct ones).

The product of its (nonzero) digits is 348364800, while the sum is 66.

The spelling of 65640490578264 in words is "sixty-five trillion, six hundred forty billion, four hundred ninety million, five hundred seventy-eight thousand, two hundred sixty-four".