20049209 has 2 divisors, whose sum is σ = 20049210. Its totient is φ = 20049208.

The previous prime is 20049187. The next prime is 20049217. The reversal of 20049209 is 90294002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19891600 + 157609 = 4460^2 + 397^2 .

It is a cyclic number.

It is not a de Polignac number, because 20049209 - 2⁸ = 20048953 is a prime.

It is not a weakly prime, because it can be changed into another prime (20049229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10024604 + 10024605.

It is an arithmetic number, because the mean of its divisors is an integer number (10024605).

Almost surely, 2^20049209 is an apocalyptic number.

It is an amenable number.

20049209 is a deficient number, since it is larger than the sum of its proper divisors (1).

20049209 is an equidigital number, since it uses as much as digits as its factorization.

20049209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 20049209 is about 4477.6343084267. The cubic root of 20049209 is about 271.6642022853.

The spelling of 20049209 in words is "twenty million, forty-nine thousand, two hundred nine".