161312197 has 2 divisors, whose sum is σ = 161312198. Its totient is φ = 161312196.

The previous prime is 161312171. The next prime is 161312227. The reversal of 161312197 is 791213161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 141943396 + 19368801 = 11914^2 + 4401^2 .

It is a cyclic number.

It is not a de Polignac number, because 161312197 - 2²⁷ = 27094469 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161312117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80656098 + 80656099.

It is an arithmetic number, because the mean of its divisors is an integer number (80656099).

Almost surely, 2^161312197 is an apocalyptic number.

It is an amenable number.

161312197 is a deficient number, since it is larger than the sum of its proper divisors (1).

161312197 is an equidigital number, since it uses as much as digits as its factorization.

161312197 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2268, while the sum is 31.

The square root of 161312197 is about 12700.8738675730. The cubic root of 161312197 is about 544.3635889815.

The spelling of 161312197 in words is "one hundred sixty-one million, three hundred twelve thousand, one hundred ninety-seven".