161780677 has 4 divisors (see below), whose sum is σ = 163015776. Its totient is φ = 160545580.

The previous prime is 161780657. The next prime is 161780681. The reversal of 161780677 is 776087161.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 776087161 = 193 ⋅4021177.

It is a cyclic number.

It is not a de Polignac number, because 161780677 - 2²³ = 153392069 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 (161780657) 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 3 ways as a sum of consecutive naturals, for example, 617353 + ... + 617614.

It is an arithmetic number, because the mean of its divisors is an integer number (40753944).

Almost surely, 2^161780677 is an apocalyptic number.

It is an amenable number.

161780677 is a deficient number, since it is larger than the sum of its proper divisors (1235099).

161780677 is a wasteful number, since it uses less digits than its factorization.

161780677 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1235098.

The product of its (nonzero) digits is 98784, while the sum is 43.

The square root of 161780677 is about 12719.3033221163. The cubic root of 161780677 is about 544.8900566599.

The spelling of 161780677 in words is "one hundred sixty-one million, seven hundred eighty thousand, six hundred seventy-seven".