20375209 has 2 divisors, whose sum is σ = 20375210. Its totient is φ = 20375208.

The previous prime is 20375189. The next prime is 20375213. The reversal of 20375209 is 90257302.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16160400 + 4214809 = 4020^2 + 2053^2 .

It is a cyclic number.

It is not a de Polignac number, because 20375209 - 2⁵ = 20375177 is a prime.

It is not a weakly prime, because it can be changed into another prime (20375219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10187604 + 10187605.

It is an arithmetic number, because the mean of its divisors is an integer number (10187605).

Almost surely, 2^20375209 is an apocalyptic number.

It is an amenable number.

20375209 is a deficient number, since it is larger than the sum of its proper divisors (1).

20375209 is an equidigital number, since it uses as much as digits as its factorization.

20375209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3780, while the sum is 28.

The square root of 20375209 is about 4513.8906721364. The cubic root of 20375209 is about 273.1287124456.

The spelling of 20375209 in words is "twenty million, three hundred seventy-five thousand, two hundred nine".