30920209 has 2 divisors, whose sum is σ = 30920210. Its totient is φ = 30920208.

The previous prime is 30920207. The next prime is 30920213. The reversal of 30920209 is 90202903.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18948609 + 11971600 = 4353^2 + 3460^2 .

It is a cyclic number.

It is not a de Polignac number, because 30920209 - 2¹ = 30920207 is a prime.

Together with 30920207, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (30920207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15460104 + 15460105.

It is an arithmetic number, because the mean of its divisors is an integer number (15460105).

Almost surely, 2^30920209 is an apocalyptic number.

It is an amenable number.

30920209 is a deficient number, since it is larger than the sum of its proper divisors (1).

30920209 is an equidigital number, since it uses as much as digits as its factorization.

30920209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 972, while the sum is 25.

The square root of 30920209 is about 5560.5943027702. The cubic root of 30920209 is about 313.8683133417.

The spelling of 30920209 in words is "thirty million, nine hundred twenty thousand, two hundred nine".