261256220227 has 4 divisors (see below), whose sum is σ = 261594198000. Its totient is φ = 260918242456.

The previous prime is 261256220221. The next prime is 261256220273. The reversal of 261256220227 is 722022652162.

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

It is a cyclic number.

It is not a de Polignac number, because 261256220227 - 2³ = 261256220219 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261256220221) 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, 168987727 + ... + 168989272.

It is an arithmetic number, because the mean of its divisors is an integer number (65398549500).

Almost surely, 2^261256220227 is an apocalyptic number.

261256220227 is a deficient number, since it is larger than the sum of its proper divisors (337977773).

261256220227 is an equidigital number, since it uses as much as digits as its factorization.

261256220227 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 337977772.

The product of its (nonzero) digits is 80640, while the sum is 37.

Adding to 261256220227 its reverse (722022652162), we get a palindrome (983278872389).

The spelling of 261256220227 in words is "two hundred sixty-one billion, two hundred fifty-six million, two hundred twenty thousand, two hundred twenty-seven".