161712591 has 8 divisors (see below), whose sum is σ = 226965120. Its totient is φ = 102134232.

The previous prime is 161712587. The next prime is 161712601. The reversal of 161712591 is 195217161.

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

It is not a de Polignac number, because 161712591 - 2² = 161712587 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161712541) 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, 1418475 + ... + 1418588.

It is an arithmetic number, because the mean of its divisors is an integer number (28370640).

Almost surely, 2^161712591 is an apocalyptic number.

161712591 is a deficient number, since it is larger than the sum of its proper divisors (65252529).

161712591 is a wasteful number, since it uses less digits than its factorization.

161712591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2837085.

The product of its digits is 3780, while the sum is 33.

The square root of 161712591 is about 12716.6265573854. The cubic root of 161712591 is about 544.8136062647.

The spelling of 161712591 in words is "one hundred sixty-one million, seven hundred twelve thousand, five hundred ninety-one".