206023661 has 4 divisors (see below), whose sum is σ = 206118972. Its totient is φ = 205928352.

The previous prime is 206023639. The next prime is 206023759. The reversal of 206023661 is 166320602.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 152646025 + 53377636 = 12355^2 + 7306^2 .

It is a cyclic number.

It is not a de Polignac number, because 206023661 - 2¹⁰ = 206022637 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 206023661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206026661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44336 + ... + 48761.

It is an arithmetic number, because the mean of its divisors is an integer number (51529743).

Almost surely, 2^206023661 is an apocalyptic number.

It is an amenable number.

206023661 is a deficient number, since it is larger than the sum of its proper divisors (95311).

206023661 is an equidigital number, since it uses as much as digits as its factorization.

206023661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95310.

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 206023661 is about 14353.5243407325. The cubic root of 206023661 is about 590.6166692217.

The spelling of 206023661 in words is "two hundred six million, twenty-three thousand, six hundred sixty-one".