261654866 has 16 divisors (see below), whose sum is σ = 438607008. Its totient is φ = 116032800.

The previous prime is 261654859. The next prime is 261654901. The reversal of 261654866 is 668456162.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 144140 + ... + 145943.

It is an arithmetic number, because the mean of its divisors is an integer number (27412938).

Almost surely, 2^261654866 is an apocalyptic number.

261654866 is a deficient number, since it is larger than the sum of its proper divisors (176952142).

261654866 is a wasteful number, since it uses less digits than its factorization.

261654866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 290137.

The product of its digits is 414720, while the sum is 44.

The square root of 261654866 is about 16175.7493180378. The cubic root of 261654866 is about 639.6016938961.

The spelling of 261654866 in words is "two hundred sixty-one million, six hundred fifty-four thousand, eight hundred sixty-six".