161406566 has 4 divisors (see below), whose sum is σ = 242109852. Its totient is φ = 80703282.

The previous prime is 161406529. The next prime is 161406587. The reversal of 161406566 is 665604161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 665604161 = 179 ⋅3718459.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 40351640 + ... + 40351643.

It is an arithmetic number, because the mean of its divisors is an integer number (60527463).

Almost surely, 2^161406566 is an apocalyptic number.

161406566 is a deficient number, since it is larger than the sum of its proper divisors (80703286).

161406566 is an equidigital number, since it uses as much as digits as its factorization.

161406566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80703285.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 161406566 is about 12704.5883837297. The cubic root of 161406566 is about 544.4697207233.

The spelling of 161406566 in words is "one hundred sixty-one million, four hundred six thousand, five hundred sixty-six".