161517791 has 8 divisors (see below), whose sum is σ = 169204800. Its totient is φ = 153972000.

The previous prime is 161517787. The next prime is 161517821. The reversal of 161517791 is 197715161.

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 161517791 - 2² = 161517787 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 (161516791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32960 + ... + 37541.

It is an arithmetic number, because the mean of its divisors is an integer number (21150600).

Almost surely, 2^161517791 is an apocalyptic number.

161517791 is a deficient number, since it is larger than the sum of its proper divisors (7687009).

161517791 is an equidigital number, since it uses as much as digits as its factorization.

161517791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70609.

The product of its digits is 13230, while the sum is 38.

The square root of 161517791 is about 12708.9649853952. The cubic root of 161517791 is about 544.5947564043.

The spelling of 161517791 in words is "one hundred sixty-one million, five hundred seventeen thousand, seven hundred ninety-one".