206898409 has 4 divisors (see below), whose sum is σ = 215894016. Its totient is φ = 197902804.

The previous prime is 206898407. The next prime is 206898421. The reversal of 206898409 is 904898602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 904898602 = 2 ⋅452449301.

It is a cyclic number.

It is not a de Polignac number, because 206898409 - 2¹ = 206898407 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (206898407) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4497769 + ... + 4497814.

It is an arithmetic number, because the mean of its divisors is an integer number (53973504).

Almost surely, 2^206898409 is an apocalyptic number.

It is an amenable number.

206898409 is a deficient number, since it is larger than the sum of its proper divisors (8995607).

206898409 is an equidigital number, since it uses as much as digits as its factorization.

206898409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8995606.

The product of its (nonzero) digits is 248832, while the sum is 46.

The square root of 206898409 is about 14383.9636053488. The cubic root of 206898409 is about 591.4513812357.

The spelling of 206898409 in words is "two hundred six million, eight hundred ninety-eight thousand, four hundred nine".