161204665 has 8 divisors (see below), whose sum is σ = 193551048. Its totient is φ = 128893440.

The previous prime is 161204627. The next prime is 161204699. The reversal of 161204665 is 566402161.

It can be written as a sum of positive squares in 4 ways, for example, as 92416 + 161112249 = 304^2 + 12693^2 .

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

It is not a de Polignac number, because 161204665 - 2¹³ = 161196473 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, 2659 + ... + 18151.

It is an arithmetic number, because the mean of its divisors is an integer number (24193881).

Almost surely, 2^161204665 is an apocalyptic number.

It is an amenable number.

161204665 is a deficient number, since it is larger than the sum of its proper divisors (32346383).

161204665 is a wasteful number, since it uses less digits than its factorization.

161204665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17579.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 161204665 is about 12696.6399098344. The cubic root of 161204665 is about 544.2426030542.

The spelling of 161204665 in words is "one hundred sixty-one million, two hundred four thousand, six hundred sixty-five".