161591203 has 6 divisors (see below), whose sum is σ = 164108684. Its totient is φ = 159076896.

The previous prime is 161591197. The next prime is 161591207. The reversal of 161591203 is 302195161.

It is not a de Polignac number, because 161591203 - 2⁹ = 161590691 is a prime.

It is a super-2 number, since 2×161591203² = 52223433773974418, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161591207) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 103275 + ... + 104827.

Almost surely, 2^161591203 is an apocalyptic number.

161591203 is a deficient number, since it is larger than the sum of its proper divisors (2517481).

161591203 is an frugal number, since it uses more digits than its factorization.

161591203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3173 (or 1620 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 28.

The square root of 161591203 is about 12711.8528547179. The cubic root of 161591203 is about 544.6772524448.

The spelling of 161591203 in words is "one hundred sixty-one million, five hundred ninety-one thousand, two hundred three".