872561 has 2 divisors, whose sum is σ = 872562. Its totient is φ = 872560.

The previous prime is 872549. The next prime is 872563. The reversal of 872561 is 165278.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 442225 + 430336 = 665^2 + 656^2 .

It is a cyclic number.

It is not a de Polignac number, because 872561 - 2¹⁸ = 610417 is a prime.

It is a super-2 number, since 2×872561² = 1522725397442, which contains 22 as substring.

Together with 872563, it forms a pair of twin primes.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 872561.

It is not a weakly prime, because it can be changed into another prime (872563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 436280 + 436281.

It is an arithmetic number, because the mean of its divisors is an integer number (436281).

2⁸⁷²⁵⁶¹ is an apocalyptic number.

It is an amenable number.

872561 is a deficient number, since it is larger than the sum of its proper divisors (1).

872561 is an equidigital number, since it uses as much as digits as its factorization.

872561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3360, while the sum is 29.

The square root of 872561 is about 934.1097365942. The cubic root of 872561 is about 95.5576071210.

The spelling of 872561 in words is "eight hundred seventy-two thousand, five hundred sixty-one".