261781683 has 16 divisors (see below), whose sum is σ = 355456416. Its totient is φ = 171325440.

The previous prime is 261781673. The next prime is 261781687. The reversal of 261781683 is 386187162.

It is not a de Polignac number, because 261781683 - 2⁵ = 261781651 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261781687) 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 15 ways as a sum of consecutive naturals, for example, 122835 + ... + 124947.

It is an arithmetic number, because the mean of its divisors is an integer number (22216026).

Almost surely, 2^261781683 is an apocalyptic number.

261781683 is a deficient number, since it is larger than the sum of its proper divisors (93674733).

261781683 is a wasteful number, since it uses less digits than its factorization.

261781683 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2854.

The product of its digits is 96768, while the sum is 42.

The square root of 261781683 is about 16179.6688161408. The cubic root of 261781683 is about 639.7050097239.

The spelling of 261781683 in words is "two hundred sixty-one million, seven hundred eighty-one thousand, six hundred eighty-three".