861506895 has 16 divisors (see below), whose sum is σ = 1422876672. Its totient is φ = 444648480.

The previous prime is 861506869. The next prime is 861506951. The reversal of 861506895 is 598605168.

It is not a de Polignac number, because 861506895 - 2¹⁵ = 861474127 is a prime.

It is a congruent number.

It is an unprimeable number.

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, 925887 + ... + 926816.

It is an arithmetic number, because the mean of its divisors is an integer number (88929792).

Almost surely, 2^861506895 is an apocalyptic number.

861506895 is a deficient number, since it is larger than the sum of its proper divisors (561369777).

861506895 is a wasteful number, since it uses less digits than its factorization.

861506895 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1852742.

The product of its (nonzero) digits is 518400, while the sum is 48.

The square root of 861506895 is about 29351.4376990293. The cubic root of 861506895 is about 951.5236473442.

The spelling of 861506895 in words is "eight hundred sixty-one million, five hundred six thousand, eight hundred ninety-five".