871649 has 2 divisors, whose sum is σ = 871650. Its totient is φ = 871648.

The previous prime is 871643. The next prime is 871657. The reversal of 871649 is 946178.

871649 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 868624 + 3025 = 932^2 + 55^2 .

It is a cyclic number.

It is not a de Polignac number, because 871649 - 2⁸ = 871393 is a prime.

It is a Chen prime.

It is a plaindrome in base 15.

It is not a weakly prime, because it can be changed into another prime (871643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 435824 + 435825.

It is an arithmetic number, because the mean of its divisors is an integer number (435825).

2⁸⁷¹⁶⁴⁹ is an apocalyptic number.

It is an amenable number.

871649 is a deficient number, since it is larger than the sum of its proper divisors (1).

871649 is an equidigital number, since it uses as much as digits as its factorization.

871649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12096, while the sum is 35.

The square root of 871649 is about 933.6214436269. The cubic root of 871649 is about 95.5243032726.

Subtracting 871649 from its reverse (946178), we obtain a square (74529 = 273²).

The spelling of 871649 in words is "eight hundred seventy-one thousand, six hundred forty-nine".