261298858277 has 4 divisors (see below), whose sum is σ = 261327353100. Its totient is φ = 261270363456.

The previous prime is 261298858273. The next prime is 261298858339. The reversal of 261298858277 is 772858892162.

It is a Cunningham number, because it is equal to 511174²+1.

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 6848224516 + 254450633761 = 82754^2 + 504431^2 .

It is a cyclic number.

It is not a de Polignac number, because 261298858277 - 2² = 261298858273 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261298858273) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14233652 + ... + 14251997.

It is an arithmetic number, because the mean of its divisors is an integer number (65331838275).

Almost surely, 2^261298858277 is an apocalyptic number.

It is an amenable number.

261298858277 is a deficient number, since it is larger than the sum of its proper divisors (28494823).

261298858277 is an equidigital number, since it uses as much as digits as its factorization.

261298858277 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28494822.

The product of its digits is 54190080, while the sum is 65.

The spelling of 261298858277 in words is "two hundred sixty-one billion, two hundred ninety-eight million, eight hundred fifty-eight thousand, two hundred seventy-seven".