2001680161 has 8 divisors (see below), whose sum is σ = 2166600744. Its totient is φ = 1838323200.

The previous prime is 2001680159. The next prime is 2001680171. The reversal of 2001680161 is 1610861002.

It can be written as a sum of positive squares in 4 ways, for example, as 226321936 + 1775358225 = 15044^2 + 42135^2 .

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 2001680161 - 2¹ = 2001680159 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2001680171) 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, 388240 + ... + 393361.

It is an arithmetic number, because the mean of its divisors is an integer number (270825093).

Almost surely, 2^2001680161 is an apocalyptic number.

It is an amenable number.

2001680161 is a deficient number, since it is larger than the sum of its proper divisors (164920583).

2001680161 is a wasteful number, since it uses less digits than its factorization.

2001680161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 781811.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 2001680161 is about 44740.1403775178. The cubic root of 2001680161 is about 1260.2737628461.

The spelling of 2001680161 in words is "two billion, one million, six hundred eighty thousand, one hundred sixty-one".