289235981 has 2 divisors, whose sum is σ = 289235982. Its totient is φ = 289235980.

The previous prime is 289235963. The next prime is 289235987. The reversal of 289235981 is 189532982.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 286117225 + 3118756 = 16915^2 + 1766^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-289235981 is a prime.

It is a super-2 number, since 2×289235981² = 167314905410064722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (289235987) 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, 144617990 + 144617991.

It is an arithmetic number, because the mean of its divisors is an integer number (144617991).

Almost surely, 2^289235981 is an apocalyptic number.

It is an amenable number.

289235981 is a deficient number, since it is larger than the sum of its proper divisors (1).

289235981 is an equidigital number, since it uses as much as digits as its factorization.

289235981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 311040, while the sum is 47.

The square root of 289235981 is about 17006.9392013966. The cubic root of 289235981 is about 661.3288051133.

The spelling of 289235981 in words is "two hundred eighty-nine million, two hundred thirty-five thousand, nine hundred eighty-one".