261688752227 has 4 divisors (see below), whose sum is σ = 299072859696. Its totient is φ = 224304644760.

The previous prime is 261688752217. The next prime is 261688752263. The reversal of 261688752227 is 722257886162.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 722257886162 = 2 ⋅361128943081.

It is not a de Polignac number, because 261688752227 - 2¹⁶ = 261688686691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261688752217) 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, 18692053724 + ... + 18692053737.

It is an arithmetic number, because the mean of its divisors is an integer number (74768214924).

Almost surely, 2^261688752227 is an apocalyptic number.

261688752227 is a deficient number, since it is larger than the sum of its proper divisors (37384107469).

261688752227 is an equidigital number, since it uses as much as digits as its factorization.

261688752227 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37384107468.

The product of its digits is 9031680, while the sum is 56.

The spelling of 261688752227 in words is "two hundred sixty-one billion, six hundred eighty-eight million, seven hundred fifty-two thousand, two hundred twenty-seven".