289721693 has 2 divisors, whose sum is σ = 289721694. Its totient is φ = 289721692.

The previous prime is 289721609. The next prime is 289721699. The reversal of 289721693 is 396127982.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 190081369 + 99640324 = 13787^2 + 9982^2 .

It is a cyclic number.

It is not a de Polignac number, because 289721693 - 2⁸ = 289721437 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (289721699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 144860846 + 144860847.

It is an arithmetic number, because the mean of its divisors is an integer number (144860847).

Almost surely, 2^289721693 is an apocalyptic number.

It is an amenable number.

289721693 is a deficient number, since it is larger than the sum of its proper divisors (1).

289721693 is an equidigital number, since it uses as much as digits as its factorization.

289721693 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592, while the sum is 47.

The square root of 289721693 is about 17021.2130296286. The cubic root of 289721693 is about 661.6987863977.

The spelling of 289721693 in words is "two hundred eighty-nine million, seven hundred twenty-one thousand, six hundred ninety-three".