206420409 has 48 divisors (see below), whose sum is σ = 345945600. Its totient is φ = 117462528.

The previous prime is 206420399. The next prime is 206420411. The reversal of 206420409 is 904024602.

It is not a de Polignac number, because 206420409 - 2⁴ = 206420393 is a prime.

It is not an unprimeable number, because it can be changed into a prime (206420209) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 116472 + ... + 118230.

It is an arithmetic number, because the mean of its divisors is an integer number (7207200).

Almost surely, 2^206420409 is an apocalyptic number.

It is an amenable number.

206420409 is a deficient number, since it is larger than the sum of its proper divisors (139525191).

206420409 is a wasteful number, since it uses less digits than its factorization.

206420409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1854 (or 1851 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 206420409 is about 14367.3382712317. The cubic root of 206420409 is about 590.9955508267.

The spelling of 206420409 in words is "two hundred six million, four hundred twenty thousand, four hundred nine".