2194478789 has 2 divisors, whose sum is σ = 2194478790. Its totient is φ = 2194478788.

The previous prime is 2194478723. The next prime is 2194478791. The reversal of 2194478789 is 9878744912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1269710689 + 924768100 = 35633^2 + 30410^2 .

It is a cyclic number.

It is not a de Polignac number, because 2194478789 - 2¹⁶ = 2194413253 is a prime.

It is a Sophie Germain prime.

Together with 2194478791, it forms a pair of twin primes.

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 (2194478719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1097239394 + 1097239395.

It is an arithmetic number, because the mean of its divisors is an integer number (1097239395).

Almost surely, 2^2194478789 is an apocalyptic number.

It is an amenable number.

2194478789 is a deficient number, since it is larger than the sum of its proper divisors (1).

2194478789 is an equidigital number, since it uses as much as digits as its factorization.

2194478789 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8128512, while the sum is 59.

The square root of 2194478789 is about 46845.2643177515. The cubic root of 2194478789 is about 1299.5025293812.

The spelling of 2194478789 in words is "two billion, one hundred ninety-four million, four hundred seventy-eight thousand, seven hundred eighty-nine".