161996331 has 8 divisors (see below), whose sum is σ = 246851584. Its totient is φ = 92569320.

The previous prime is 161996309. The next prime is 161996347. The reversal of 161996331 is 133699161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 161996331 - 2¹⁰ = 161995307 is a prime.

It is a super-2 number, since 2×161996331² = 52485622514923122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 161996331.

It is not an unprimeable number, because it can be changed into a prime (161996231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3857035 + ... + 3857076.

It is an arithmetic number, because the mean of its divisors is an integer number (30856448).

Almost surely, 2^161996331 is an apocalyptic number.

161996331 is a deficient number, since it is larger than the sum of its proper divisors (84855253).

161996331 is an equidigital number, since it uses as much as digits as its factorization.

161996331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7714121.

The product of its digits is 26244, while the sum is 39.

The square root of 161996331 is about 12727.7779286095. Note that the first 3 decimals coincide. The cubic root of 161996331 is about 545.1320623769.

The spelling of 161996331 in words is "one hundred sixty-one million, nine hundred ninety-six thousand, three hundred thirty-one".