65721655601 has 8 divisors (see below), whose sum is σ = 78376136064. Its totient is φ = 53883593280.

The previous prime is 65721655567. The next prime is 65721655627. The reversal of 65721655601 is 10655612756.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 65721655601 - 2³⁰ = 64647913777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65721655661) 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 7 ways as a sum of consecutive naturals, for example, 204104360 + ... + 204104681.

It is an arithmetic number, because the mean of its divisors is an integer number (9797017008).

Almost surely, 2^65721655601 is an apocalyptic number.

It is an amenable number.

65721655601 is a deficient number, since it is larger than the sum of its proper divisors (12654480463).

65721655601 is a wasteful number, since it uses less digits than its factorization.

65721655601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 408209071.

The product of its (nonzero) digits is 378000, while the sum is 44.

The spelling of 65721655601 in words is "sixty-five billion, seven hundred twenty-one million, six hundred fifty-five thousand, six hundred one".