66511721710756 has 24 divisors (see below), whose sum is σ = 133106531233536. Its totient is φ = 28487219059200.

The previous prime is 66511721710601. The next prime is 66511721710769. The reversal of 66511721710756 is 65701712711566.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 66511721710697 and 66511721710706.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 741809836 + ... + 741899491.

It is an arithmetic number, because the mean of its divisors is an integer number (5546105468064).

Almost surely, 2^{66511721710756} is an apocalyptic number.

It is an amenable number.

66511721710756 is an abundant number, since it is smaller than the sum of its proper divisors (66594809522780).

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

66511721710756 is a wasteful number, since it uses less digits than its factorization.

66511721710756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1483710939 (or 1483710937 counting only the distinct ones).

The product of its (nonzero) digits is 3704400, while the sum is 55.

The spelling of 66511721710756 in words is "sixty-six trillion, five hundred eleven billion, seven hundred twenty-one million, seven hundred ten thousand, seven hundred fifty-six".