261600210561 has 16 divisors (see below), whose sum is σ = 357013730304. Its totient is φ = 170295729744.

The previous prime is 261600210491. The next prime is 261600210589. The reversal of 261600210561 is 165012006162.

261600210561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 261600210561 - 2⁷ = 261600210433 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261600210161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 167500 + ... + 742466.

It is an arithmetic number, because the mean of its divisors is an integer number (22313358144).

Almost surely, 2^261600210561 is an apocalyptic number.

It is an amenable number.

261600210561 is a deficient number, since it is larger than the sum of its proper divisors (95413519743).

261600210561 is a wasteful number, since it uses less digits than its factorization.

261600210561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 578540.

The product of its (nonzero) digits is 4320, while the sum is 30.

The spelling of 261600210561 in words is "two hundred sixty-one billion, six hundred million, two hundred ten thousand, five hundred sixty-one".