161979778078 has 16 divisors (see below), whose sum is σ = 246970514304. Its totient is φ = 79656464160.

The previous prime is 161979778067. The next prime is 161979778091. The reversal of 161979778078 is 870877979161.

It is a junction number, because it is equal to n+sod(n) for n = 161979777998 and 161979778016.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2025876 + ... + 2104312.

It is an arithmetic number, because the mean of its divisors is an integer number (15435657144).

Almost surely, 2^161979778078 is an apocalyptic number.

161979778078 is a deficient number, since it is larger than the sum of its proper divisors (84990736226).

161979778078 is a wasteful number, since it uses less digits than its factorization.

161979778078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95427.

The product of its (nonzero) digits is 74680704, while the sum is 70.

The spelling of 161979778078 in words is "one hundred sixty-one billion, nine hundred seventy-nine million, seven hundred seventy-eight thousand, seventy-eight".