206557440 has 72 divisors (see below), whose sum is σ = 659705088. Its totient is φ = 55080960.

The previous prime is 206557427. The next prime is 206557447. The reversal of 206557440 is 44755602.

It is not an unprimeable number, because it can be changed into a prime (206557447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23056 + ... + 30735.

Almost surely, 2^206557440 is an apocalyptic number.

206557440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

206557440 is an abundant number, since it is smaller than the sum of its proper divisors (453147648).

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

206557440 is an equidigital number, since it uses as much as digits as its factorization.

206557440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53815 (or 53801 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 33.

The square root of 206557440 is about 14372.1063174470. The cubic root of 206557440 is about 591.1262982302.

The spelling of 206557440 in words is "two hundred six million, five hundred fifty-seven thousand, four hundred forty".