261138786 has 8 divisors (see below), whose sum is σ = 522277584. Its totient is φ = 87046260.

The previous prime is 261138769. The next prime is 261138847. The reversal of 261138786 is 687831162.

It is a sphenic number, since it is the product of 3 distinct primes.

261138786 is an admirable number.

It is a Curzon number.

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 3 ways as a sum of consecutive naturals, for example, 21761560 + ... + 21761571.

It is an arithmetic number, because the mean of its divisors is an integer number (65284698).

Almost surely, 2^261138786 is an apocalyptic number.

261138786 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

261138786 is a wasteful number, since it uses less digits than its factorization.

261138786 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43523136.

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

The square root of 261138786 is about 16159.7891694168. The cubic root of 261138786 is about 639.1809068975.

The spelling of 261138786 in words is "two hundred sixty-one million, one hundred thirty-eight thousand, seven hundred eighty-six".