181680493 has 2 divisors, whose sum is σ = 181680494. Its totient is φ = 181680492.

The previous prime is 181680481. The next prime is 181680503. The reversal of 181680493 is 394086181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 158080329 + 23600164 = 12573^2 + 4858^2 .

It is a cyclic number.

It is not a de Polignac number, because 181680493 - 2¹³ = 181672301 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (181680403) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90840246 + 90840247.

It is an arithmetic number, because the mean of its divisors is an integer number (90840247).

Almost surely, 2^181680493 is an apocalyptic number.

It is an amenable number.

181680493 is a deficient number, since it is larger than the sum of its proper divisors (1).

181680493 is an equidigital number, since it uses as much as digits as its factorization.

181680493 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 41472, while the sum is 40.

The square root of 181680493 is about 13478.8906442630. The cubic root of 181680493 is about 566.3732933935.

The spelling of 181680493 in words is "one hundred eighty-one million, six hundred eighty thousand, four hundred ninety-three".