861245871 has 16 divisors (see below), whose sum is σ = 1160568960. Its totient is φ = 568075680.

The previous prime is 861245843. The next prime is 861245893. The reversal of 861245871 is 178542168.

It is not a de Polignac number, because 861245871 - 2⁷ = 861245743 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861245771) 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, 108136 + ... + 115826.

It is an arithmetic number, because the mean of its divisors is an integer number (72535560).

Almost surely, 2^861245871 is an apocalyptic number.

861245871 is a deficient number, since it is larger than the sum of its proper divisors (299323089).

861245871 is a wasteful number, since it uses less digits than its factorization.

861245871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8086.

The product of its digits is 107520, while the sum is 42.

The square root of 861245871 is about 29346.9908338146. The cubic root of 861245871 is about 951.4275383835.

The spelling of 861245871 in words is "eight hundred sixty-one million, two hundred forty-five thousand, eight hundred seventy-one".