561871 has 6 divisors (see below), whose sum is σ = 575016. Its totient is φ = 549000.

The previous prime is 561839. The next prime is 561907. The reversal of 561871 is 178165.

It is a happy number.

561871 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 561871 - 2⁵ = 561839 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (562871) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3646 + ... + 3796.

It is an arithmetic number, because the mean of its divisors is an integer number (95836).

2⁵⁶¹⁸⁷¹ is an apocalyptic number.

561871 is a deficient number, since it is larger than the sum of its proper divisors (13145).

561871 is an equidigital number, since it uses as much as digits as its factorization.

561871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273 (or 212 counting only the distinct ones).

The product of its digits is 1680, while the sum is 28.

The square root of 561871 is about 749.5805493741. The cubic root of 561871 is about 82.5174006761.

The spelling of 561871 in words is "five hundred sixty-one thousand, eight hundred seventy-one".