206663641 has 8 divisors (see below), whose sum is σ = 209369160. Its totient is φ = 203970048.

The previous prime is 206663621. The next prime is 206663651. The reversal of 206663641 is 146366602.

It can be written as a sum of positive squares in 4 ways, for example, as 67305616 + 139358025 = 8204^2 + 11805^2 .

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

It is not a de Polignac number, because 206663641 - 2⁹ = 206663129 is a prime.

It is a super-2 number, since 2×206663641² = 85419721022753762, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 206663597 and 206663606.

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, 34995 + ... + 40471.

It is an arithmetic number, because the mean of its divisors is an integer number (26171145).

Almost surely, 2^206663641 is an apocalyptic number.

It is an amenable number.

206663641 is a deficient number, since it is larger than the sum of its proper divisors (2705519).

206663641 is an equidigital number, since it uses as much as digits as its factorization.

206663641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5963.

The product of its (nonzero) digits is 31104, while the sum is 34.

The square root of 206663641 is about 14375.8005342311. The cubic root of 206663641 is about 591.2275895836.

The spelling of 206663641 in words is "two hundred six million, six hundred sixty-three thousand, six hundred forty-one".