261280866 has 48 divisors (see below), whose sum is σ = 656453952. Its totient is φ = 67863840.

The previous prime is 261280853. The next prime is 261280867. The reversal of 261280866 is 668082162.

261280866 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261280867) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20625 + ... + 30788.

It is an arithmetic number, because the mean of its divisors is an integer number (13676124).

Almost surely, 2^261280866 is an apocalyptic number.

261280866 is an abundant number, since it is smaller than the sum of its proper divisors (395173086).

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

261280866 is a wasteful number, since it uses less digits than its factorization.

261280866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51447 (or 51436 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 39.

The square root of 261280866 is about 16164.1846685813. The cubic root of 261280866 is about 639.2968074109.

The spelling of 261280866 in words is "two hundred sixty-one million, two hundred eighty thousand, eight hundred sixty-six".