653997209 has 2 divisors, whose sum is σ = 653997210. Its totient is φ = 653997208.

The previous prime is 653997199. The next prime is 653997221. The reversal of 653997209 is 902799356.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 406627225 + 247369984 = 20165^2 + 15728^2 .

It is a cyclic number.

It is not a de Polignac number, because 653997209 - 2⁴ = 653997193 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (653997269) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 326998604 + 326998605.

It is an arithmetic number, because the mean of its divisors is an integer number (326998605).

Almost surely, 2^653997209 is an apocalyptic number.

It is an amenable number.

653997209 is a deficient number, since it is larger than the sum of its proper divisors (1).

653997209 is an equidigital number, since it uses as much as digits as its factorization.

653997209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 918540, while the sum is 50.

The square root of 653997209 is about 25573.3691366625. The cubic root of 653997209 is about 868.0111387819.

The spelling of 653997209 in words is "six hundred fifty-three million, nine hundred ninety-seven thousand, two hundred nine".