194731289 has 2 divisors, whose sum is σ = 194731290. Its totient is φ = 194731288.

The previous prime is 194731253. The next prime is 194731291. The reversal of 194731289 is 982137491.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 100000000 + 94731289 = 10000^2 + 9733^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-194731289 is a prime.

Together with 194731291, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (194731489) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97365644 + 97365645.

It is an arithmetic number, because the mean of its divisors is an integer number (97365645).

Almost surely, 2^194731289 is an apocalyptic number.

It is an amenable number.

194731289 is a deficient number, since it is larger than the sum of its proper divisors (1).

194731289 is an equidigital number, since it uses as much as digits as its factorization.

194731289 is an evil number, because the sum of its binary digits is even.

The product of its digits is 108864, while the sum is 44.

The square root of 194731289 is about 13954.6153297036. The cubic root of 194731289 is about 579.6225139826.

The spelling of 194731289 in words is "one hundred ninety-four million, seven hundred thirty-one thousand, two hundred eighty-nine".