203145309 has 6 divisors (see below), whose sum is σ = 293432126. Its totient is φ = 135430200.

The previous prime is 203145301. The next prime is 203145323. The reversal of 203145309 is 903541302.

203145309 is a `hidden beast` number, since 203 + 1 + 453 + 0 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 123543225 + 79602084 = 11115^2 + 8922^2 .

It is not a de Polignac number, because 203145309 - 2³ = 203145301 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (203145301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11285842 + ... + 11285859.

Almost surely, 2^203145309 is an apocalyptic number.

It is an amenable number.

203145309 is a deficient number, since it is larger than the sum of its proper divisors (90286817).

203145309 is a wasteful number, since it uses less digits than its factorization.

203145309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22571707 (or 22571704 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 27.

The square root of 203145309 is about 14252.9052827836. The cubic root of 203145309 is about 587.8532623568.

The spelling of 203145309 in words is "two hundred three million, one hundred forty-five thousand, three hundred nine".