161945885 has 4 divisors (see below), whose sum is σ = 194335068. Its totient is φ = 129556704.

The previous prime is 161945881. The next prime is 161945909. The reversal of 161945885 is 588549161.

161945885 = T₈₀₄₆ + T₈₀₄₇ + ... + T₈₀₅₀.

It is a happy number.

161945885 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 588549161 = 281 ⋅2094481.

It can be written as a sum of positive squares in 2 ways, for example, as 72624484 + 89321401 = 8522^2 + 9451^2 .

It is a cyclic number.

It is not a de Polignac number, because 161945885 - 2² = 161945881 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161945881) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16194584 + ... + 16194593.

It is an arithmetic number, because the mean of its divisors is an integer number (48583767).

Almost surely, 2^161945885 is an apocalyptic number.

It is an amenable number.

161945885 is a deficient number, since it is larger than the sum of its proper divisors (32389183).

161945885 is an equidigital number, since it uses as much as digits as its factorization.

161945885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32389182.

The product of its digits is 345600, while the sum is 47.

The square root of 161945885 is about 12725.7960458275. The cubic root of 161945885 is about 545.0754714101.

The spelling of 161945885 in words is "one hundred sixty-one million, nine hundred forty-five thousand, eight hundred eighty-five".