161090194 has 4 divisors (see below), whose sum is σ = 241635294. Its totient is φ = 80545096.

The previous prime is 161090173. The next prime is 161090213. The reversal of 161090194 is 491090161.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 105781225 + 55308969 = 10285^2 + 7437^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 40272547 + ... + 40272550.

Almost surely, 2^161090194 is an apocalyptic number.

161090194 is a deficient number, since it is larger than the sum of its proper divisors (80545100).

161090194 is an equidigital number, since it uses as much as digits as its factorization.

161090194 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80545099.

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

The square root of 161090194 is about 12692.1311843205. The cubic root of 161090194 is about 544.1137508129.

The spelling of 161090194 in words is "one hundred sixty-one million, ninety thousand, one hundred ninety-four".