206445840 has 80 divisors (see below), whose sum is σ = 641381568. Its totient is φ = 54931968.

The previous prime is 206445839. The next prime is 206445851. The reversal of 206445840 is 48544602.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 188334 + ... + 189426.

Almost surely, 2^206445840 is an apocalyptic number.

206445840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

206445840 is an abundant number, since it is smaller than the sum of its proper divisors (434935728).

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

206445840 is a wasteful number, since it uses less digits than its factorization.

206445840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1896 (or 1890 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 33.

The square root of 206445840 is about 14368.2232722073. The cubic root of 206445840 is about 591.0198200527.

The spelling of 206445840 in words is "two hundred six million, four hundred forty-five thousand, eight hundred forty".