281688193 has 2 divisors, whose sum is σ = 281688194. Its totient is φ = 281688192.

The previous prime is 281688161. The next prime is 281688221. The reversal of 281688193 is 391886182.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 272646144 + 9042049 = 16512^2 + 3007^2 .

It is a cyclic number.

It is not a de Polignac number, because 281688193 - 2⁵ = 281688161 is a prime.

It is not a weakly prime, because it can be changed into another prime (281688493) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140844096 + 140844097.

It is an arithmetic number, because the mean of its divisors is an integer number (140844097).

Almost surely, 2^281688193 is an apocalyptic number.

It is an amenable number.

281688193 is a deficient number, since it is larger than the sum of its proper divisors (1).

281688193 is an equidigital number, since it uses as much as digits as its factorization.

281688193 is an evil number, because the sum of its binary digits is even.

The product of its digits is 165888, while the sum is 46.

The square root of 281688193 is about 16783.5691377013. The cubic root of 281688193 is about 655.5254358543.

The spelling of 281688193 in words is "two hundred eighty-one million, six hundred eighty-eight thousand, one hundred ninety-three".