161296778 has 4 divisors (see below), whose sum is σ = 241945170. Its totient is φ = 80648388.

The previous prime is 161296777. The next prime is 161296781. The reversal of 161296778 is 877692161.

161296778 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 877692161 = 67 ⋅13099883.

It can be written as a sum of positive squares in only one way, i.e., 88416409 + 72880369 = 9403^2 + 8537^2 .

It is not an unprimeable number, because it can be changed into a prime (161296777) 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 as a sum of consecutive naturals, namely, 40324193 + ... + 40324196.

Almost surely, 2^161296778 is an apocalyptic number.

161296778 is a deficient number, since it is larger than the sum of its proper divisors (80648392).

161296778 is an equidigital number, since it uses as much as digits as its factorization.

161296778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80648391.

The product of its digits is 254016, while the sum is 47.

The square root of 161296778 is about 12700.2668475903. The cubic root of 161296778 is about 544.3462441273.

The spelling of 161296778 in words is "one hundred sixty-one million, two hundred ninety-six thousand, seven hundred seventy-eight".