65664136512 has 336 divisors, whose sum is σ = 217000888832. Its totient is φ = 19550730240.

The previous prime is 65664136493. The next prime is 65664136519. The reversal of 65664136512 is 21563146656.

65664136512 is a `hidden beast` number, since 6 + 5 + 66 + 41 + 36 + 512 = 666.

It is a super-2 number, since 2×65664136512² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65664136519) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6262218 + ... + 6272694.

Almost surely, 2^65664136512 is an apocalyptic number.

65664136512 is a gapful number since it is divisible by the number (62) 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 65664136512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108500444416).

65664136512 is an abundant number, since it is smaller than the sum of its proper divisors (151336752320).

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

65664136512 is a wasteful number, since it uses less digits than its factorization.

65664136512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10548 (or 10526 counting only the distinct ones).

The product of its digits is 777600, while the sum is 45.

The spelling of 65664136512 in words is "sixty-five billion, six hundred sixty-four million, one hundred thirty-six thousand, five hundred twelve".