64811335680 has 1536 divisors, whose sum is σ = 301230316800. Its totient is φ = 13079937024.

The previous prime is 64811335649. The next prime is 64811335681. The reversal of 64811335680 is 8653311846.

64811335680 is a `hidden beast` number, since 6 + 4 + 81 + 1 + 3 + 3 + 568 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1536).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64811335681) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2817884149 + ... + 2817884171.

Almost surely, 2^64811335680 is an apocalyptic number.

64811335680 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 64811335680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (150615158400).

64811335680 is an abundant number, since it is smaller than the sum of its proper divisors (236418981120).

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

64811335680 is a wasteful number, since it uses less digits than its factorization.

64811335680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94 (or 53 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 45.

The spelling of 64811335680 in words is "sixty-four billion, eight hundred eleven million, three hundred thirty-five thousand, six hundred eighty".