1994547209 has 2 divisors, whose sum is σ = 1994547210. Its totient is φ = 1994547208.

The previous prime is 1994547169. The next prime is 1994547241. The reversal of 1994547209 is 9027454991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1730809609 + 263737600 = 41603^2 + 16240^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1994547209 is a prime.

It is not a weakly prime, because it can be changed into another prime (1994547259) 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, 997273604 + 997273605.

It is an arithmetic number, because the mean of its divisors is an integer number (997273605).

Almost surely, 2^1994547209 is an apocalyptic number.

It is an amenable number.

1994547209 is a deficient number, since it is larger than the sum of its proper divisors (1).

1994547209 is an equidigital number, since it uses as much as digits as its factorization.

1994547209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 816480, while the sum is 50.

The square root of 1994547209 is about 44660.3538835061. The cubic root of 1994547209 is about 1258.7749933683.

The spelling of 1994547209 in words is "one billion, nine hundred ninety-four million, five hundred forty-seven thousand, two hundred nine".