261226321 has 4 divisors (see below), whose sum is σ = 261310644. Its totient is φ = 261142000.

The previous prime is 261226309. The next prime is 261226349. The reversal of 261226321 is 123622162.

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 198499921 + 62726400 = 14089^2 + 7920^2 .

It is a cyclic number.

It is not a de Polignac number, because 261226321 - 2⁵ = 261226289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261226351) 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, 37330 + ... + 43771.

It is an arithmetic number, because the mean of its divisors is an integer number (65327661).

Almost surely, 2^261226321 is an apocalyptic number.

It is an amenable number.

261226321 is a deficient number, since it is larger than the sum of its proper divisors (84323).

261226321 is an equidigital number, since it uses as much as digits as its factorization.

261226321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84322.

The product of its digits is 1728, while the sum is 25.

The square root of 261226321 is about 16162.4973627221. The cubic root of 261226321 is about 639.2523177758.

Adding to 261226321 its reverse (123622162), we get a palindrome (384848483).

The spelling of 261226321 in words is "two hundred sixty-one million, two hundred twenty-six thousand, three hundred twenty-one".