206666401 has 4 divisors (see below), whose sum is σ = 217543600. Its totient is φ = 195789204.

The previous prime is 206666359. The next prime is 206666413. The reversal of 206666401 is 104666602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 206666401 - 2²¹ = 204569249 is a prime.

It is a super-2 number, since 2×206666401² = 85422002604585602, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (206666461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5438571 + ... + 5438608.

It is an arithmetic number, because the mean of its divisors is an integer number (54385900).

Almost surely, 2^206666401 is an apocalyptic number.

It is an amenable number.

206666401 is a deficient number, since it is larger than the sum of its proper divisors (10877199).

206666401 is a wasteful number, since it uses less digits than its factorization.

206666401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10877198.

The product of its (nonzero) digits is 10368, while the sum is 31.

The square root of 206666401 is about 14375.8965285647. The cubic root of 206666401 is about 591.2302215268.

The spelling of 206666401 in words is "two hundred six million, six hundred sixty-six thousand, four hundred one".