261886866 has 16 divisors (see below), whose sum is σ = 524697888. Its totient is φ = 87141600.

The previous prime is 261886841. The next prime is 261886897. The reversal of 261886866 is 668688162.

261886866 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34795 + ... + 41646.

It is an arithmetic number, because the mean of its divisors is an integer number (32793618).

Almost surely, 2^261886866 is an apocalyptic number.

261886866 is an abundant number, since it is smaller than the sum of its proper divisors (262811022).

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

261886866 is a wasteful number, since it uses less digits than its factorization.

261886866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77017.

The product of its digits is 1327104, while the sum is 51.

The square root of 261886866 is about 16182.9189579631. The cubic root of 261886866 is about 639.7906753588.

The spelling of 261886866 in words is "two hundred sixty-one million, eight hundred eighty-six thousand, eight hundred sixty-six".