161795856789 has 18 divisors (see below), whose sum is σ = 271861066230. Its totient is φ = 92454775056.

The previous prime is 161795856773. The next prime is 161795856811. The reversal of 161795856789 is 987658597161.

161795856789 is a `hidden beast` number, since 1 + 6 + 1 + 7 + 9 + 58 + 567 + 8 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 151749202500 + 10046654289 = 389550^2 + 100233^2 .

It is not a de Polignac number, because 161795856789 - 2⁴ = 161795856773 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161795896789) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 183441574 + ... + 183442455.

Almost surely, 2^161795856789 is an apocalyptic number.

It is an amenable number.

161795856789 is a deficient number, since it is larger than the sum of its proper divisors (110065209441).

161795856789 is a wasteful number, since it uses less digits than its factorization.

161795856789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 366884049 (or 366884039 counting only the distinct ones).

The product of its digits is 228614400, while the sum is 72.

The spelling of 161795856789 in words is "one hundred sixty-one billion, seven hundred ninety-five million, eight hundred fifty-six thousand, seven hundred eighty-nine".