161855197 has 8 divisors (see below), whose sum is σ = 185682816. Its totient is φ = 138203952.

The previous prime is 161855189. The next prime is 161855261. The reversal of 161855197 is 791558161.

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 161855197 - 2³ = 161855189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161855137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42118 + ... + 45799.

It is an arithmetic number, because the mean of its divisors is an integer number (23210352).

Almost surely, 2^161855197 is an apocalyptic number.

It is an amenable number.

161855197 is a deficient number, since it is larger than the sum of its proper divisors (23827619).

161855197 is an equidigital number, since it uses as much as digits as its factorization.

161855197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88187.

The product of its digits is 75600, while the sum is 43.

The square root of 161855197 is about 12722.2323905830. The cubic root of 161855197 is about 544.9737068930.

The spelling of 161855197 in words is "one hundred sixty-one million, eight hundred fifty-five thousand, one hundred ninety-seven".