20894609 has 2 divisors, whose sum is σ = 20894610. Its totient is φ = 20894608.

The previous prime is 20894597. The next prime is 20894617. The reversal of 20894609 is 90649802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13712209 + 7182400 = 3703^2 + 2680^2 .

It is a cyclic number.

It is not a de Polignac number, because 20894609 - 2⁴ = 20894593 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 (20894009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10447304 + 10447305.

It is an arithmetic number, because the mean of its divisors is an integer number (10447305).

Almost surely, 2^20894609 is an apocalyptic number.

It is an amenable number.

20894609 is a deficient number, since it is larger than the sum of its proper divisors (1).

20894609 is an equidigital number, since it uses as much as digits as its factorization.

20894609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 38.

The square root of 20894609 is about 4571.0621304025. The cubic root of 20894609 is about 275.4301104114.

The spelling of 20894609 in words is "twenty million, eight hundred ninety-four thousand, six hundred nine".