263609161 has 4 divisors (see below), whose sum is σ = 265378500. Its totient is φ = 261839824.

The previous prime is 263609153. The next prime is 263609167. The reversal of 263609161 is 161906362.

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 173738761 + 89870400 = 13181^2 + 9480^2 .

It is a cyclic number.

It is not a de Polignac number, because 263609161 - 2³ = 263609153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (263609167) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 884446 + ... + 884743.

It is an arithmetic number, because the mean of its divisors is an integer number (66344625).

Almost surely, 2^263609161 is an apocalyptic number.

It is an amenable number.

263609161 is a deficient number, since it is larger than the sum of its proper divisors (1769339).

263609161 is a wasteful number, since it uses less digits than its factorization.

263609161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1769338.

The product of its (nonzero) digits is 11664, while the sum is 34.

The square root of 263609161 is about 16236.0451157294. The cubic root of 263609161 is about 641.1901365383.

The spelling of 263609161 in words is "two hundred sixty-three million, six hundred nine thousand, one hundred sixty-one".