161886281 has 4 divisors (see below), whose sum is σ = 162075600. Its totient is φ = 161696964.

The previous prime is 161886239. The next prime is 161886313. The reversal of 161886281 is 182688161.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 161886281 - 2⁶ = 161886217 is a prime.

It is a super-2 number, since 2×161886281² = 52414335952021922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (161886481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 93371 + ... + 95088.

It is an arithmetic number, because the mean of its divisors is an integer number (40518900).

Almost surely, 2^161886281 is an apocalyptic number.

It is an amenable number.

161886281 is a deficient number, since it is larger than the sum of its proper divisors (189319).

161886281 is an equidigital number, since it uses as much as digits as its factorization.

161886281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189318.

The product of its digits is 36864, while the sum is 41.

The square root of 161886281 is about 12723.4539728802. The cubic root of 161886281 is about 545.0085917339.

The spelling of 161886281 in words is "one hundred sixty-one million, eight hundred eighty-six thousand, two hundred eighty-one".