206577661 has 2 divisors, whose sum is σ = 206577662. Its totient is φ = 206577660.

The previous prime is 206577647. The next prime is 206577667. The reversal of 206577661 is 166775602.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 151536100 + 55041561 = 12310^2 + 7419^2 .

It is a cyclic number.

It is not a de Polignac number, because 206577661 - 2⁷ = 206577533 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (206577667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103288830 + 103288831.

It is an arithmetic number, because the mean of its divisors is an integer number (103288831).

Almost surely, 2^206577661 is an apocalyptic number.

It is an amenable number.

206577661 is a deficient number, since it is larger than the sum of its proper divisors (1).

206577661 is an equidigital number, since it uses as much as digits as its factorization.

206577661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 105840, while the sum is 40.

The square root of 206577661 is about 14372.8097809718. The cubic root of 206577661 is about 591.1455870938.

The spelling of 206577661 in words is "two hundred six million, five hundred seventy-seven thousand, six hundred sixty-one".