161606109983617 has 8 divisors (see below), whose sum is σ = 174082238962856. Its totient is φ = 149136393825792.

The previous prime is 161606109983611. The next prime is 161606109983663. The reversal of 161606109983617 is 716389901606161.

It can be written as a sum of positive squares in 4 ways, for example, as 12263436682561 + 149342673301056 = 3501919^2 + 12220584^2 .

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 161606109983617 - 2¹⁹ = 161606109459329 is a prime.

It is a super-2 number, since 2×161606109983617² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161606109983611) 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, 1603153008 + ... + 1603253809.

It is an arithmetic number, because the mean of its divisors is an integer number (21760279870357).

Almost surely, 2^{161606109983617} is an apocalyptic number.

It is an amenable number.

161606109983617 is a deficient number, since it is larger than the sum of its proper divisors (12476128979239).

161606109983617 is a wasteful number, since it uses less digits than its factorization.

161606109983617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3206410707.

The product of its (nonzero) digits is 17635968, while the sum is 64.

The spelling of 161606109983617 in words is "one hundred sixty-one trillion, six hundred six billion, one hundred nine million, nine hundred eighty-three thousand, six hundred seventeen".