161181763364644 has 81 divisors (see below), whose sum is σ = 315418040693553. Its totient is φ = 72015304231200.

The previous prime is 161181763364599. The next prime is 161181763364663. The reversal of 161181763364644 is 446463367181161.

The square root of 161181763364644 is 12695738.

It is a perfect power (a square), and thus also a powerful number.

161181763364644 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 69419924387044 + 91761838977600 = 8331862^2 + 9579240^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 16479063034 + ... + 16479072814.

Almost surely, 2^{161181763364644} is an apocalyptic number.

161181763364644 is the 12695738-th square number.

It is an amenable number.

161181763364644 is a deficient number, since it is larger than the sum of its proper divisors (154236277328909).

161181763364644 is an frugal number, since it uses more digits than its factorization.

161181763364644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19706 (or 9853 counting only the distinct ones).

The product of its digits is 41803776, while the sum is 61.

The spelling of 161181763364644 in words is "one hundred sixty-one trillion, one hundred eighty-one billion, seven hundred sixty-three million, three hundred sixty-four thousand, six hundred forty-four".