65799776640 has 512 divisors, whose sum is σ = 234760458240. Its totient is φ = 15566929920.

The previous prime is 65799776639. The next prime is 65799776657. The reversal of 65799776640 is 4667799756.

65799776640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×65799776640² (a number of 22 digits) contains 22 as substring.

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, 214331367 + ... + 214331673.

It is an arithmetic number, because the mean of its divisors is an integer number (458516520).

Almost surely, 2^65799776640 is an apocalyptic number.

65799776640 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 65799776640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117380229120).

65799776640 is an abundant number, since it is smaller than the sum of its proper divisors (168960681600).

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

65799776640 is a wasteful number, since it uses less digits than its factorization.

65799776640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 650 (or 638 counting only the distinct ones).

The product of its (nonzero) digits is 120022560, while the sum is 66.

The spelling of 65799776640 in words is "sixty-five billion, seven hundred ninety-nine million, seven hundred seventy-six thousand, six hundred forty".