261109277128 has 32 divisors (see below), whose sum is σ = 559554091200. Its totient is φ = 111897133632.

The previous prime is 261109277119. The next prime is 261109277129. The reversal of 261109277128 is 821772901162.

261109277128 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (261109277129) 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 7 ways as a sum of consecutive naturals, for example, 841626 + ... + 1109302.

It is an arithmetic number, because the mean of its divisors is an integer number (17486065350).

Almost surely, 2^261109277128 is an apocalyptic number.

261109277128 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

261109277128 is an abundant number, since it is smaller than the sum of its proper divisors (298444814072).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261109277128 is a wasteful number, since it uses less digits than its factorization.

261109277128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 285109 (or 285105 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 46.

The spelling of 261109277128 in words is "two hundred sixty-one billion, one hundred nine million, two hundred seventy-seven thousand, one hundred twenty-eight".