181642273 has 2 divisors, whose sum is σ = 181642274. Its totient is φ = 181642272.

The previous prime is 181642271. The next prime is 181642291. The reversal of 181642273 is 372246181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 99341089 + 82301184 = 9967^2 + 9072^2 .

It is a cyclic number.

It is not a de Polignac number, because 181642273 - 2¹ = 181642271 is a prime.

Together with 181642271, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (181642271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90821136 + 90821137.

It is an arithmetic number, because the mean of its divisors is an integer number (90821137).

Almost surely, 2^181642273 is an apocalyptic number.

It is an amenable number.

181642273 is a deficient number, since it is larger than the sum of its proper divisors (1).

181642273 is an equidigital number, since it uses as much as digits as its factorization.

181642273 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16128, while the sum is 34.

The square root of 181642273 is about 13477.4727972272. The cubic root of 181642273 is about 566.3335747552. Note that the first 3 decimals are identical.

The spelling of 181642273 in words is "one hundred eighty-one million, six hundred forty-two thousand, two hundred seventy-three".