206140661 has 4 divisors (see below), whose sum is σ = 211168524. Its totient is φ = 201112800.

The previous prime is 206140609. The next prime is 206140663. The reversal of 206140661 is 166041602.

It is a happy number.

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 93122500 + 113018161 = 9650^2 + 10631^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-206140661 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 206140661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206140663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2513870 + ... + 2513951.

It is an arithmetic number, because the mean of its divisors is an integer number (52792131).

Almost surely, 2^206140661 is an apocalyptic number.

It is an amenable number.

206140661 is a deficient number, since it is larger than the sum of its proper divisors (5027863).

206140661 is an equidigital number, since it uses as much as digits as its factorization.

206140661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5027862.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 206140661 is about 14357.5994163370. The cubic root of 206140661 is about 590.7284509998.

The spelling of 206140661 in words is "two hundred six million, one hundred forty thousand, six hundred sixty-one".