161947689 has 8 divisors (see below), whose sum is σ = 222895872. Its totient is φ = 104482320.

The previous prime is 161947673. The next prime is 161947699. The reversal of 161947689 is 986749161.

It is a happy number.

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

It is not a de Polignac number, because 161947689 - 2⁴ = 161947673 is a prime.

It is a super-3 number, since 3×161947689³ (a number of 26 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (161947609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 870594 + ... + 870779.

It is an arithmetic number, because the mean of its divisors is an integer number (27861984).

Almost surely, 2^161947689 is an apocalyptic number.

It is an amenable number.

161947689 is a deficient number, since it is larger than the sum of its proper divisors (60948183).

161947689 is a wasteful number, since it uses less digits than its factorization.

161947689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1741407.

The product of its digits is 653184, while the sum is 51.

The square root of 161947689 is about 12725.8669252825. The cubic root of 161947689 is about 545.0774953629.

The spelling of 161947689 in words is "one hundred sixty-one million, nine hundred forty-seven thousand, six hundred eighty-nine".