161113129321 has 9 divisors (see below), whose sum is σ = 166872384133. Its totient is φ = 155546265280.

The previous prime is 161113129313. The next prime is 161113129327. The reversal of 161113129321 is 123921311161.

The square root of 161113129321 is 401389.

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

It can be written as a sum of positive squares in 4 ways, for example, as 4249605721 + 156863523600 = 65189^2 + 396060^2 .

It is not a de Polignac number, because 161113129321 - 2³ = 161113129313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161113129327) 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, 11633361 + ... + 11647201.

Almost surely, 2^161113129321 is an apocalyptic number.

161113129321 is the 401389-th square number.

161113129321 is the 200695-th centered octagonal number.

It is an amenable number.

161113129321 is a deficient number, since it is larger than the sum of its proper divisors (5759254812).

161113129321 is an frugal number, since it uses more digits than its factorization.

161113129321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27740 (or 13870 counting only the distinct ones).

The product of its digits is 1944, while the sum is 31.

The spelling of 161113129321 in words is "one hundred sixty-one billion, one hundred thirteen million, one hundred twenty-nine thousand, three hundred twenty-one".