671721516601 has 8 divisors (see below), whose sum is σ = 692349311808. Its totient is φ = 651403914000.

The previous prime is 671721516569. The next prime is 671721516607. The reversal of 671721516601 is 106615127176.

It is a happy number.

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 671721516601 - 2⁵ = 671721516569 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (671721516607) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 77543755 + ... + 77552416.

It is an arithmetic number, because the mean of its divisors is an integer number (86543663976).

Almost surely, 2^671721516601 is an apocalyptic number.

671721516601 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

671721516601 is a deficient number, since it is larger than the sum of its proper divisors (20627795207).

671721516601 is a wasteful number, since it uses less digits than its factorization.

671721516601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155096303.

The product of its (nonzero) digits is 105840, while the sum is 43.

The spelling of 671721516601 in words is "six hundred seventy-one billion, seven hundred twenty-one million, five hundred sixteen thousand, six hundred one".