161717839 has 4 divisors (see below), whose sum is σ = 161867160. Its totient is φ = 161568520.

The previous prime is 161717837. The next prime is 161717851. The reversal of 161717839 is 938717161.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 938717161 = 1097 ⋅855713.

It is a cyclic number.

It is not a de Polignac number, because 161717839 - 2¹ = 161717837 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 161717795 and 161717804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161717837) 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, 73024 + ... + 75205.

It is an arithmetic number, because the mean of its divisors is an integer number (40466790).

Almost surely, 2^161717839 is an apocalyptic number.

161717839 is a deficient number, since it is larger than the sum of its proper divisors (149321).

161717839 is a wasteful number, since it uses less digits than its factorization.

161717839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149320.

The product of its digits is 63504, while the sum is 43.

The square root of 161717839 is about 12716.8328997436. The cubic root of 161717839 is about 544.8194997470.

The spelling of 161717839 in words is "one hundred sixty-one million, seven hundred seventeen thousand, eight hundred thirty-nine".