161812237 has 2 divisors, whose sum is σ = 161812238. Its totient is φ = 161812236.

The previous prime is 161812223. The next prime is 161812243. The reversal of 161812237 is 732218161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 129481641 + 32330596 = 11379^2 + 5686^2 .

It is a cyclic number.

It is not a de Polignac number, because 161812237 - 2⁷ = 161812109 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 161812199 and 161812208.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161812247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80906118 + 80906119.

It is an arithmetic number, because the mean of its divisors is an integer number (80906119).

Almost surely, 2^161812237 is an apocalyptic number.

It is an amenable number.

161812237 is a deficient number, since it is larger than the sum of its proper divisors (1).

161812237 is an equidigital number, since it uses as much as digits as its factorization.

161812237 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4032, while the sum is 31.

The square root of 161812237 is about 12720.5438956045. The cubic root of 161812237 is about 544.9254865443.

The spelling of 161812237 in words is "one hundred sixty-one million, eight hundred twelve thousand, two hundred thirty-seven".