20430409 has 2 divisors, whose sum is σ = 20430410. Its totient is φ = 20430408.

The previous prime is 20430373. The next prime is 20430439. The reversal of 20430409 is 90403402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20430400 + 9 = 4520^2 + 3^2 .

It is a cyclic number.

It is not a de Polignac number, because 20430409 - 2¹⁷ = 20299337 is a prime.

It is a super-2 number, since 2×20430409² = 834803223814562, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20430409.

It is not a weakly prime, because it can be changed into another prime (20430439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10215204 + 10215205.

It is an arithmetic number, because the mean of its divisors is an integer number (10215205).

Almost surely, 2^20430409 is an apocalyptic number.

It is an amenable number.

20430409 is a deficient number, since it is larger than the sum of its proper divisors (1).

20430409 is an equidigital number, since it uses as much as digits as its factorization.

20430409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 20430409 is about 4520.0009955751. Note that the first 3 decimals coincide. The cubic root of 20430409 is about 273.3751411692.

The spelling of 20430409 in words is "twenty million, four hundred thirty thousand, four hundred nine".