261820227 has 4 divisors (see below), whose sum is σ = 349093640. Its totient is φ = 174546816.

The previous prime is 261820193. The next prime is 261820271. The reversal of 261820227 is 722028162.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 261820227 - 2¹⁰ = 261819203 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261820194 and 261820203.

It is not an unprimeable number, because it can be changed into a prime (261820297) 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, 43636702 + ... + 43636707.

It is an arithmetic number, because the mean of its divisors is an integer number (87273410).

Almost surely, 2^261820227 is an apocalyptic number.

261820227 is a deficient number, since it is larger than the sum of its proper divisors (87273413).

261820227 is an equidigital number, since it uses as much as digits as its factorization.

261820227 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87273412.

The product of its (nonzero) digits is 5376, while the sum is 30.

The square root of 261820227 is about 16180.8598968040. The cubic root of 261820227 is about 639.7364043063.

Adding to 261820227 its reverse (722028162), we get a palindrome (983848389).

The spelling of 261820227 in words is "two hundred sixty-one million, eight hundred twenty thousand, two hundred twenty-seven".