194004721 has 2 divisors, whose sum is σ = 194004722. Its totient is φ = 194004720.

The previous prime is 194004647. The next prime is 194004749. The reversal of 194004721 is 127400491.

It is an a-pointer prime, because the next prime (194004749) can be obtained adding 194004721 to its sum of digits (28).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 166126321 + 27878400 = 12889^2 + 5280^2 .

It is a cyclic number.

It is not a de Polignac number, because 194004721 - 2⁷ = 194004593 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 194004721.

It is not a weakly prime, because it can be changed into another prime (194004761) 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, 97002360 + 97002361.

It is an arithmetic number, because the mean of its divisors is an integer number (97002361).

Almost surely, 2^194004721 is an apocalyptic number.

It is an amenable number.

194004721 is a deficient number, since it is larger than the sum of its proper divisors (1).

194004721 is an equidigital number, since it uses as much as digits as its factorization.

194004721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 194004721 is about 13928.5577501764. The cubic root of 194004721 is about 578.9007329898.

The spelling of 194004721 in words is "one hundred ninety-four million, four thousand, seven hundred twenty-one".