209791161 has 16 divisors (see below), whose sum is σ = 311139520. Its totient is φ = 139708800.

The previous prime is 209791159. The next prime is 209791163. The reversal of 209791161 is 161197902.

It is an interprime number because it is at equal distance from previous prime (209791159) and next prime (209791163).

It is not a de Polignac number, because 209791161 - 2¹ = 209791159 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (209791163) 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 15 ways as a sum of consecutive naturals, for example, 24681 + ... + 32073.

It is an arithmetic number, because the mean of its divisors is an integer number (19446220).

Almost surely, 2^209791161 is an apocalyptic number.

It is an amenable number.

209791161 is a deficient number, since it is larger than the sum of its proper divisors (101348359).

209791161 is a wasteful number, since it uses less digits than its factorization.

209791161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8453 (or 8447 counting only the distinct ones).

The product of its (nonzero) digits is 6804, while the sum is 36.

The square root of 209791161 is about 14484.1693237824. The cubic root of 209791161 is about 594.1950945730.

The spelling of 209791161 in words is "two hundred nine million, seven hundred ninety-one thousand, one hundred sixty-one".