65785781864 has 48 divisors (see below), whose sum is σ = 136287839520. Its totient is φ = 29523867360.

The previous prime is 65785781861. The next prime is 65785781869. The reversal of 65785781864 is 46818758756.

65785781864 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 65785781864.

It is not an unprimeable number, because it can be changed into a prime (65785781861) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 489317 + ... + 609099.

It is an arithmetic number, because the mean of its divisors is an integer number (2839329990).

Almost surely, 2^65785781864 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 65785781864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68143919760).

65785781864 is an abundant number, since it is smaller than the sum of its proper divisors (70502057656).

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

65785781864 is a wasteful number, since it uses less digits than its factorization.

65785781864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119958 (or 119875 counting only the distinct ones).

The product of its digits is 90316800, while the sum is 65.

The spelling of 65785781864 in words is "sixty-five billion, seven hundred eighty-five million, seven hundred eighty-one thousand, eight hundred sixty-four".