161131665 has 8 divisors (see below), whose sum is σ = 257810688. Its totient is φ = 85936880.

The previous prime is 161131657. The next prime is 161131667. The reversal of 161131665 is 566131161.

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

It is not a de Polignac number, because 161131665 - 2³ = 161131657 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161131667) 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, 5371041 + ... + 5371070.

It is an arithmetic number, because the mean of its divisors is an integer number (32226336).

Almost surely, 2^161131665 is an apocalyptic number.

161131665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161131665 is a deficient number, since it is larger than the sum of its proper divisors (96679023).

161131665 is a wasteful number, since it uses less digits than its factorization.

161131665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10742119.

The product of its digits is 3240, while the sum is 30.

The square root of 161131665 is about 12693.7648079677. The cubic root of 161131665 is about 544.1604389543.

The spelling of 161131665 in words is "one hundred sixty-one million, one hundred thirty-one thousand, six hundred sixty-five".