65509541856 has 576 divisors, whose sum is σ = 224087834880. Its totient is φ = 18617610240.

The previous prime is 65509541849. The next prime is 65509541869. The reversal of 65509541856 is 65814590556.

65509541856 is a `hidden beast` number, since 6 + 5 + 509 + 54 + 1 + 85 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 281156716 + ... + 281156948.

It is an arithmetic number, because the mean of its divisors is an integer number (389041380).

Almost surely, 2^65509541856 is an apocalyptic number.

65509541856 is a gapful number since it is divisible by the number (66) 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 65509541856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112043917440).

65509541856 is an abundant number, since it is smaller than the sum of its proper divisors (158578293024).

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

65509541856 is a wasteful number, since it uses less digits than its factorization.

65509541856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 461 (or 441 counting only the distinct ones).

The product of its (nonzero) digits is 6480000, while the sum is 54.

The spelling of 65509541856 in words is "sixty-five billion, five hundred nine million, five hundred forty-one thousand, eight hundred fifty-six".