209261 has 4 divisors (see below), whose sum is σ = 225372. Its totient is φ = 193152.

The previous prime is 209257. The next prime is 209263. The reversal of 209261 is 162902.

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 72361 + 136900 = 269^2 + 370^2 .

It is a cyclic number.

It is not a de Polignac number, because 209261 - 2² = 209257 is a prime.

It is a super-2 number, since 2×209261² = 87580332242, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209263) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8036 + ... + 8061.

It is an arithmetic number, because the mean of its divisors is an integer number (56343).

2²⁰⁹²⁶¹ is an apocalyptic number.

It is an amenable number.

209261 is a deficient number, since it is larger than the sum of its proper divisors (16111).

209261 is a wasteful number, since it uses less digits than its factorization.

209261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16110.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 209261 is about 457.4505437750. The cubic root of 209261 is about 59.3694144330.

The spelling of 209261 in words is "two hundred nine thousand, two hundred sixty-one".