206161261 has 8 divisors (see below), whose sum is σ = 225816120. Its totient is φ = 187342848.

The previous prime is 206161237. The next prime is 206161279. The reversal of 206161261 is 162161602.

206161261 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 61921161 + 144240100 = 7869^2 + 12010^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 206161261 - 2⁹ = 206160749 is a prime.

It is a super-2 number, since 2×206161261² = 85004931074220242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206161231) 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, 208596 + ... + 209581.

It is an arithmetic number, because the mean of its divisors is an integer number (28227015).

Almost surely, 2^206161261 is an apocalyptic number.

It is an amenable number.

206161261 is a deficient number, since it is larger than the sum of its proper divisors (19654859).

206161261 is a wasteful number, since it uses less digits than its factorization.

206161261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 418223.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 206161261 is about 14358.3167885376. The cubic root of 206161261 is about 590.7481278566.

The spelling of 206161261 in words is "two hundred six million, one hundred sixty-one thousand, two hundred sixty-one".