161551065665 has 8 divisors (see below), whose sum is σ = 211485031488. Its totient is φ = 117491684080.

The previous prime is 161551065659. The next prime is 161551065677. The reversal of 161551065665 is 566560155161.

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

It is not a de Polignac number, because 161551065665 - 2⁴ = 161551065649 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1468645997 + ... + 1468646106.

It is an arithmetic number, because the mean of its divisors is an integer number (26435628936).

Almost surely, 2^161551065665 is an apocalyptic number.

It is an amenable number.

161551065665 is a deficient number, since it is larger than the sum of its proper divisors (49933965823).

161551065665 is a wasteful number, since it uses less digits than its factorization.

161551065665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2937292119.

The product of its (nonzero) digits is 810000, while the sum is 47.

The spelling of 161551065665 in words is "one hundred sixty-one billion, five hundred fifty-one million, sixty-five thousand, six hundred sixty-five".