261185886 has 96 divisors (see below), whose sum is σ = 634390848. Its totient is φ = 77137920.

The previous prime is 261185879. The next prime is 261185887. The reversal of 261185886 is 688581162.

261185886 is a `hidden beast` number, since 2 + 61 + 1 + 8 + 588 + 6 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261185887) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 839671 + ... + 839981.

It is an arithmetic number, because the mean of its divisors is an integer number (6608238).

Almost surely, 2^261185886 is an apocalyptic number.

261185886 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 261185886, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (317195424).

261185886 is an abundant number, since it is smaller than the sum of its proper divisors (373204962).

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

261185886 is a wasteful number, since it uses less digits than its factorization.

261185886 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 466 (or 463 counting only the distinct ones).

The product of its digits is 184320, while the sum is 45.

The square root of 261185886 is about 16161.2464247038. The cubic root of 261185886 is about 639.2193329663.

The spelling of 261185886 in words is "two hundred sixty-one million, one hundred eighty-five thousand, eight hundred eighty-six".