1681994012161 has 8 divisors (see below), whose sum is σ = 1698938928000. Its totient is φ = 1665054812400.

The previous prime is 1681994012123. The next prime is 1681994012207. The reversal of 1681994012161 is 1612104991861.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1681994012161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1681994015161) 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, 836311 + ... + 2015788.

It is an arithmetic number, because the mean of its divisors is an integer number (212367366000).

Almost surely, 2^{1681994012161} is an apocalyptic number.

It is an amenable number.

1681994012161 is a deficient number, since it is larger than the sum of its proper divisors (16944915839).

1681994012161 is a wasteful number, since it uses less digits than its factorization.

1681994012161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2858039.

The product of its (nonzero) digits is 186624, while the sum is 49.

The spelling of 1681994012161 in words is "one trillion, six hundred eighty-one billion, nine hundred ninety-four million, twelve thousand, one hundred sixty-one".