261783858 has 32 divisors (see below), whose sum is σ = 599122944. Its totient is φ = 74700432.

The previous prime is 261783857. The next prime is 261783889. The reversal of 261783858 is 858387162.

It is not an unprimeable number, because it can be changed into a prime (261783857) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 33741 + ... + 40767.

It is an arithmetic number, because the mean of its divisors is an integer number (18722592).

Almost surely, 2^261783858 is an apocalyptic number.

261783858 is an abundant number, since it is smaller than the sum of its proper divisors (337339086).

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

261783858 is a wasteful number, since it uses less digits than its factorization.

261783858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7926.

The product of its digits is 645120, while the sum is 48.

The square root of 261783858 is about 16179.7360299852. The cubic root of 261783858 is about 639.7067813713.

The spelling of 261783858 in words is "two hundred sixty-one million, seven hundred eighty-three thousand, eight hundred fifty-eight".