145775209 has 2 divisors, whose sum is σ = 145775210. Its totient is φ = 145775208.

The previous prime is 145775207. The next prime is 145775251. The reversal of 145775209 is 902577541.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 145733184 + 42025 = 12072^2 + 205^2 .

It is a cyclic number.

It is not a de Polignac number, because 145775209 - 2¹ = 145775207 is a prime.

Together with 145775207, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (145775207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 72887604 + 72887605.

It is an arithmetic number, because the mean of its divisors is an integer number (72887605).

Almost surely, 2^145775209 is an apocalyptic number.

It is an amenable number.

145775209 is a deficient number, since it is larger than the sum of its proper divisors (1).

145775209 is an equidigital number, since it uses as much as digits as its factorization.

145775209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 88200, while the sum is 40.

The square root of 145775209 is about 12073.7404726125. The cubic root of 145775209 is about 526.2933601900.

The spelling of 145775209 in words is "one hundred forty-five million, seven hundred seventy-five thousand, two hundred nine".