261859788 has 36 divisors (see below), whose sum is σ = 663285168. Its totient is φ = 87107040.

The previous prime is 261859783. The next prime is 261859811. The reversal of 261859788 is 887958162.

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (261859783) 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 11 ways as a sum of consecutive naturals, for example, 10878 + ... + 25338.

It is an arithmetic number, because the mean of its divisors is an integer number (18424588).

Almost surely, 2^261859788 is an apocalyptic number.

It is an amenable number.

261859788 is an abundant number, since it is smaller than the sum of its proper divisors (401425380).

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

261859788 is a wasteful number, since it uses less digits than its factorization.

261859788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14974 (or 14969 counting only the distinct ones).

The product of its digits is 1935360, while the sum is 54.

The square root of 261859788 is about 16182.0823134725. The cubic root of 261859788 is about 639.7686240442.

The spelling of 261859788 in words is "two hundred sixty-one million, eight hundred fifty-nine thousand, seven hundred eighty-eight".