206664621 has 8 divisors (see below), whose sum is σ = 275622624. Its totient is φ = 137741520.

The previous prime is 206664613. The next prime is 206664677. The reversal of 206664621 is 126466602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 206664621 - 2³ = 206664613 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206663621) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12406 + ... + 23816.

It is an arithmetic number, because the mean of its divisors is an integer number (34452828).

Almost surely, 2^206664621 is an apocalyptic number.

It is an amenable number.

206664621 is a deficient number, since it is larger than the sum of its proper divisors (68958003).

206664621 is a wasteful number, since it uses less digits than its factorization.

206664621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17451.

The product of its (nonzero) digits is 20736, while the sum is 33.

The square root of 206664621 is about 14375.8346192491. The cubic root of 206664621 is about 591.2285241169.

The spelling of 206664621 in words is "two hundred six million, six hundred sixty-four thousand, six hundred twenty-one".