65509361280 has 1536 divisors, whose sum is σ = 287165088000. Its totient is φ = 14014218240.

The previous prime is 65509361243. The next prime is 65509361327. The reversal of 65509361280 is 8216390556.

65509361280 is a `hidden beast` number, since 6 + 5 + 5 + 0 + 9 + 361 + 280 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 675354192 + ... + 675354288.

Almost surely, 2^65509361280 is an apocalyptic number.

65509361280 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 65509361280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (143582544000).

65509361280 is an abundant number, since it is smaller than the sum of its proper divisors (221655726720).

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

65509361280 is a wasteful number, since it uses less digits than its factorization.

65509361280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183 (or 154 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 45.

The spelling of 65509361280 in words is "sixty-five billion, five hundred nine million, three hundred sixty-one thousand, two hundred eighty".