871644657 has 16 divisors (see below), whose sum is σ = 1278224640. Its totient is φ = 524982912.

The previous prime is 871644649. The next prime is 871644659. The reversal of 871644657 is 756446178.

It is not a de Polignac number, because 871644657 - 2³ = 871644649 is a prime.

It is not an unprimeable number, because it can be changed into a prime (871644659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 235932 + ... + 239597.

It is an arithmetic number, because the mean of its divisors is an integer number (79889040).

Almost surely, 2^871644657 is an apocalyptic number.

It is an amenable number.

871644657 is a deficient number, since it is larger than the sum of its proper divisors (406579983).

871644657 is a wasteful number, since it uses less digits than its factorization.

871644657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 475592.

The product of its digits is 1128960, while the sum is 48.

The square root of 871644657 is about 29523.6287911903. The cubic root of 871644657 is about 955.2414462203.

The spelling of 871644657 in words is "eight hundred seventy-one million, six hundred forty-four thousand, six hundred fifty-seven".