20473909 has 2 divisors, whose sum is σ = 20473910. Its totient is φ = 20473908.

The previous prime is 20473907. The next prime is 20473931. The reversal of 20473909 is 90937402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18232900 + 2241009 = 4270^2 + 1497^2 .

It is a cyclic number.

It is not a de Polignac number, because 20473909 - 2¹ = 20473907 is a prime.

Together with 20473907, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20473907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10236954 + 10236955.

It is an arithmetic number, because the mean of its divisors is an integer number (10236955).

Almost surely, 2^20473909 is an apocalyptic number.

It is an amenable number.

20473909 is a deficient number, since it is larger than the sum of its proper divisors (1).

20473909 is an equidigital number, since it uses as much as digits as its factorization.

20473909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13608, while the sum is 34.

The square root of 20473909 is about 4524.8103827674. The cubic root of 20473909 is about 273.5690251760.

The spelling of 20473909 in words is "twenty million, four hundred seventy-three thousand, nine hundred nine".