261646126640211 has 32 divisors (see below), whose sum is σ = 351343344540672. Its totient is φ = 173195229957120.

The previous prime is 261646126640207. The next prime is 261646126640221. The reversal of 261646126640211 is 112046621646162.

It is not a de Polignac number, because 261646126640211 - 2² = 261646126640207 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261646126640201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 280115491 + ... + 281048003.

It is an arithmetic number, because the mean of its divisors is an integer number (10979479516896).

Almost surely, 2^{261646126640211} is an apocalyptic number.

261646126640211 is a deficient number, since it is larger than the sum of its proper divisors (89697217900461).

261646126640211 is a wasteful number, since it uses less digits than its factorization.

261646126640211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 933963.

The product of its (nonzero) digits is 995328, while the sum is 48.

The spelling of 261646126640211 in words is "two hundred sixty-one trillion, six hundred forty-six billion, one hundred twenty-six million, six hundred forty thousand, two hundred eleven".