161440829209 has 9 divisors (see below), whose sum is σ = 177456348181. Its totient is φ = 146760372220.

The previous prime is 161440829197. The next prime is 161440829213. The reversal of 161440829209 is 902928044161.

The square root of 161440829209 is 401797.

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

It is not a de Polignac number, because 161440829209 - 2⁹ = 161440828697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161440829509) 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, 4401504 + ... + 4438030.

Almost surely, 2^161440829209 is an apocalyptic number.

161440829209 is the 401797-th square number.

161440829209 is the 200899-th centered octagonal number.

It is an amenable number.

161440829209 is a deficient number, since it is larger than the sum of its proper divisors (16015518972).

161440829209 is an frugal number, since it uses more digits than its factorization.

161440829209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73076 (or 36538 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 46.

The spelling of 161440829209 in words is "one hundred sixty-one billion, four hundred forty million, eight hundred twenty-nine thousand, two hundred nine".