206161605 has 40 divisors (see below), whose sum is σ = 398001912. Its totient is φ = 101492352.

The previous prime is 206161591. The next prime is 206161633. The reversal of 206161605 is 506161602.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 20493729 + 185667876 = 4527^2 + 13626^2 .

It is not a de Polignac number, because 206161605 - 2⁷ = 206161477 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 14314 + ... + 24843.

Almost surely, 2^206161605 is an apocalyptic number.

It is an amenable number.

206161605 is a deficient number, since it is larger than the sum of its proper divisors (191840307).

206161605 is a wasteful number, since it uses less digits than its factorization.

206161605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39187 (or 39178 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 206161605 is about 14358.3287676526. The cubic root of 206161605 is about 590.7484564298.

The spelling of 206161605 in words is "two hundred six million, one hundred sixty-one thousand, six hundred five".