206443840 has 28 divisors (see below), whose sum is σ = 491595156. Its totient is φ = 82577408.

The previous prime is 206443823. The next prime is 206443847. The reversal of 206443840 is 48344602.

It can be written as a sum of positive squares in 2 ways, for example, as 40755456 + 165688384 = 6384^2 + 12872^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206443847) 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, 322249 + ... + 322888.

Almost surely, 2^206443840 is an apocalyptic number.

206443840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

206443840 is an abundant number, since it is smaller than the sum of its proper divisors (285151316).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

206443840 is an equidigital number, since it uses as much as digits as its factorization.

206443840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 645154 (or 645144 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 31.

The square root of 206443840 is about 14368.1536740111. The cubic root of 206443840 is about 591.0179114917.

The spelling of 206443840 in words is "two hundred six million, four hundred forty-three thousand, eight hundred forty".