161386189441 has 9 divisors (see below), whose sum is σ = 166773000513. Its totient is φ = 156168131460.

The previous prime is 161386189439. The next prime is 161386189463. The reversal of 161386189441 is 144981683161.

It is a happy number.

The square root of 161386189441 is 401729.

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

It is not a de Polignac number, because 161386189441 - 2¹ = 161386189439 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161386189141) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 12447120 + ... + 12460078.

Almost surely, 2^161386189441 is an apocalyptic number.

161386189441 is the 401729-th square number.

161386189441 is the 200865-th centered octagonal number.

It is an amenable number.

161386189441 is a deficient number, since it is larger than the sum of its proper divisors (5386811072).

161386189441 is an frugal number, since it uses more digits than its factorization.

161386189441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25980 (or 12990 counting only the distinct ones).

The product of its digits is 995328, while the sum is 52.

The spelling of 161386189441 in words is "one hundred sixty-one billion, three hundred eighty-six million, one hundred eighty-nine thousand, four hundred forty-one".