65905660800 has 384 divisors, whose sum is σ = 275655571200. Its totient is φ = 15064012800.

The previous prime is 65905660787. The next prime is 65905660811. The reversal of 65905660800 is 806650956.

65905660800 is a `hidden beast` number, since 6 + 5 + 9 + 0 + 566 + 0 + 80 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a super-2 number, since 2×65905660800² (a number of 22 digits) contains 22 as substring.

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 polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 550315 + ... + 659285.

It is an arithmetic number, because the mean of its divisors is an integer number (717853050).

Almost surely, 2^65905660800 is an apocalyptic number.

65905660800 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 65905660800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (137827785600).

65905660800 is an abundant number, since it is smaller than the sum of its proper divisors (209749910400).

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

65905660800 is a wasteful number, since it uses less digits than its factorization.

65905660800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109011 (or 108988 counting only the distinct ones).

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

The spelling of 65905660800 in words is "sixty-five billion, nine hundred five million, six hundred sixty thousand, eight hundred".