205661131 has 8 divisors (see below), whose sum is σ = 226632560. Its totient is φ = 185425632.

The previous prime is 205661129. The next prime is 205661153. The reversal of 205661131 is 131166502.

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

It is not a de Polignac number, because 205661131 - 2¹ = 205661129 is a prime.

It is a super-2 number, since 2×205661131² = 84593001608398322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 205661096 and 205661105.

It is not an unprimeable number, because it can be changed into a prime (205661171) 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, 183396 + ... + 184513.

It is an arithmetic number, because the mean of its divisors is an integer number (28329070).

Almost surely, 2^205661131 is an apocalyptic number.

205661131 is a deficient number, since it is larger than the sum of its proper divisors (20971429).

205661131 is a wasteful number, since it uses less digits than its factorization.

205661131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 367965.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 205661131 is about 14340.8901746021. The cubic root of 205661131 is about 590.2700391744.

The spelling of 205661131 in words is "two hundred five million, six hundred sixty-one thousand, one hundred thirty-one".