181957 has 2 divisors, whose sum is σ = 181958. Its totient is φ = 181956.

The previous prime is 181943. The next prime is 181967. The reversal of 181957 is 759181.

181957 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 136161 + 45796 = 369^2 + 214^2 .

It is an emirp because it is prime and its reverse (759181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 181957 - 2¹¹ = 179909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (181927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90978 + 90979.

It is an arithmetic number, because the mean of its divisors is an integer number (90979).

2¹⁸¹⁹⁵⁷ is an apocalyptic number.

It is an amenable number.

181957 is a deficient number, since it is larger than the sum of its proper divisors (1).

181957 is an equidigital number, since it uses as much as digits as its factorization.

181957 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2520, while the sum is 31.

The square root of 181957 is about 426.5641803996. The cubic root of 181957 is about 56.6660476672. Note that the first 3 decimals are identical.

The spelling of 181957 in words is "one hundred eighty-one thousand, nine hundred fifty-seven".