20194409 has 2 divisors, whose sum is σ = 20194410. Its totient is φ = 20194408.

The previous prime is 20194399. The next prime is 20194507. The reversal of 20194409 is 90449102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13579225 + 6615184 = 3685^2 + 2572^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20194409 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (20194309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10097204 + 10097205.

It is an arithmetic number, because the mean of its divisors is an integer number (10097205).

Almost surely, 2^20194409 is an apocalyptic number.

It is an amenable number.

20194409 is a deficient number, since it is larger than the sum of its proper divisors (1).

20194409 is an equidigital number, since it uses as much as digits as its factorization.

20194409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 20194409 is about 4493.8189772175. The cubic root of 20194409 is about 272.3184392230.

The spelling of 20194409 in words is "twenty million, one hundred ninety-four thousand, four hundred nine".