161269756835209 has 9 divisors (see below), whose sum is σ = 177263605272999. Its totient is φ = 146608742858160.

The previous prime is 161269756835207. The next prime is 161269756835227. The reversal of 161269756835209 is 902538657962161.

The square root of 161269756835209 is 12699203.

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

It can be written as a sum of positive squares in only one way, i.e., 131411488345225 + 29858268489984 = 11463485^2 + 5464272^2 .

It is not a de Polignac number, because 161269756835209 - 2¹ = 161269756835207 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161269756835207) 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, 139113997 + ... + 140268469.

Almost surely, 2^{161269756835209} is an apocalyptic number.

161269756835209 is the 12699203-rd square number.

161269756835209 is the 6349602-nd centered octagonal number.

It is an amenable number.

161269756835209 is a deficient number, since it is larger than the sum of its proper divisors (15993848437790).

161269756835209 is an frugal number, since it uses more digits than its factorization.

161269756835209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2308968 (or 1154484 counting only the distinct ones).

The product of its (nonzero) digits is 293932800, while the sum is 70.

The spelling of 161269756835209 in words is "one hundred sixty-one trillion, two hundred sixty-nine billion, seven hundred fifty-six million, eight hundred thirty-five thousand, two hundred nine".