209638469 has 2 divisors, whose sum is σ = 209638470. Its totient is φ = 209638468.

The previous prime is 209638433. The next prime is 209638531. The reversal of 209638469 is 964836902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 205578244 + 4060225 = 14338^2 + 2015^2 .

It is a cyclic number.

It is not a de Polignac number, because 209638469 - 2²⁰ = 208589893 is a prime.

It is a super-2 number, since 2×209638469² = 87896575369327922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (209638369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104819234 + 104819235.

It is an arithmetic number, because the mean of its divisors is an integer number (104819235).

Almost surely, 2^209638469 is an apocalyptic number.

It is an amenable number.

209638469 is a deficient number, since it is larger than the sum of its proper divisors (1).

209638469 is an equidigital number, since it uses as much as digits as its factorization.

209638469 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 559872, while the sum is 47.

The square root of 209638469 is about 14478.8973682391. The cubic root of 209638469 is about 594.0509021969.

The spelling of 209638469 in words is "two hundred nine million, six hundred thirty-eight thousand, four hundred sixty-nine".