261534560810 has 16 divisors (see below), whose sum is σ = 498454104456. Its totient is φ = 98460069888.

The previous prime is 261534560753. The next prime is 261534560821. The reversal of 261534560810 is 18065435162.

261534560810 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 206727536929 + 54807023881 = 454673^2 + 234109^2 .

It is a super-2 number, since 2×261534560810² (a number of 24 digits) contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 769219127 + ... + 769219466.

Almost surely, 2^261534560810 is an apocalyptic number.

261534560810 is a deficient number, since it is larger than the sum of its proper divisors (236919543646).

261534560810 is a wasteful number, since it uses less digits than its factorization.

261534560810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1538438617.

The product of its (nonzero) digits is 172800, while the sum is 41.

Adding to 261534560810 its reverse (18065435162), we get a palindrome (279599995972).

The spelling of 261534560810 in words is "two hundred sixty-one billion, five hundred thirty-four million, five hundred sixty thousand, eight hundred ten".