161868672908645 has 16 divisors (see below), whose sum is σ = 207979312722480. Its totient is φ = 120508177895424.

The previous prime is 161868672908617. The next prime is 161868672908651. The reversal of 161868672908645 is 546809276868161.

It is a Cunningham number, because it is equal to 12722762²+1.

It can be written as a sum of positive squares in 8 ways, for example, as 213900700036 + 161654772208609 = 462494^2 + 12714353^2 .

It is a cyclic number.

It is not a de Polignac number, because 161868672908645 - 2³⁴ = 161851493039461 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10698516752 + ... + 10698531881.

It is an arithmetic number, because the mean of its divisors is an integer number (12998707045155).

Almost surely, 2^{161868672908645} is an apocalyptic number.

It is an amenable number.

161868672908645 is a deficient number, since it is larger than the sum of its proper divisors (46110639813835).

161868672908645 is a wasteful number, since it uses less digits than its factorization.

161868672908645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21397048744.

The product of its (nonzero) digits is 1672151040, while the sum is 77.

The spelling of 161868672908645 in words is "one hundred sixty-one trillion, eight hundred sixty-eight billion, six hundred seventy-two million, nine hundred eight thousand, six hundred forty-five".