65491918128 has 240 divisors, whose sum is σ = 225921928960. Its totient is φ = 17246670336.

The previous prime is 65491918111. The next prime is 65491918139. The reversal of 65491918128 is 82181919456.

65491918128 is a `hidden beast` number, since 6 + 549 + 1 + 91 + 8 + 1 + 2 + 8 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 9680475 + ... + 9687237.

Almost surely, 2^65491918128 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 65491918128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112960964480).

65491918128 is an abundant number, since it is smaller than the sum of its proper divisors (160430010832).

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

65491918128 is a wasteful number, since it uses less digits than its factorization.

65491918128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7536 (or 7527 counting only the distinct ones).

The product of its digits is 1244160, while the sum is 54.

The spelling of 65491918128 in words is "sixty-five billion, four hundred ninety-one million, nine hundred eighteen thousand, one hundred twenty-eight".