206663640 has 64 divisors (see below), whose sum is σ = 621561600. Its totient is φ = 54970752.

The previous prime is 206663621. The next prime is 206663651. The reversal of 206663640 is 46366602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50719 + ... + 54641.

It is an arithmetic number, because the mean of its divisors is an integer number (9711900).

Almost surely, 2^206663640 is an apocalyptic number.

206663640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

206663640 is an abundant number, since it is smaller than the sum of its proper divisors (414897960).

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

206663640 is a wasteful number, since it uses less digits than its factorization.

206663640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4376 (or 4372 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 33.

The square root of 206663640 is about 14375.8004994505. The cubic root of 206663640 is about 591.2275886300.

The spelling of 206663640 in words is "two hundred six million, six hundred sixty-three thousand, six hundred forty".