161015191 has 4 divisors (see below), whose sum is σ = 161049312. Its totient is φ = 160981072.

The previous prime is 161015171. The next prime is 161015207. The reversal of 161015191 is 191510161.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161015191 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 (161015171) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8575 + ... + 19888.

It is an arithmetic number, because the mean of its divisors is an integer number (40262328).

Almost surely, 2^161015191 is an apocalyptic number.

161015191 is a deficient number, since it is larger than the sum of its proper divisors (34121).

161015191 is an equidigital number, since it uses as much as digits as its factorization.

161015191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34120.

The product of its (nonzero) digits is 270, while the sum is 25.

The square root of 161015191 is about 12689.1761355889. The cubic root of 161015191 is about 544.0292919186.

The spelling of 161015191 in words is "one hundred sixty-one million, fifteen thousand, one hundred ninety-one".