825561 has 24 divisors (see below), whose sum is σ = 1347840. Its totient is φ = 482400.

The previous prime is 825553. The next prime is 825577. The reversal of 825561 is 165528.

825561 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 825561 - 2³ = 825553 is a prime.

825561 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (825551) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2935 + ... + 3203.

It is an arithmetic number, because the mean of its divisors is an integer number (56160).

2⁸²⁵⁵⁶¹ is an apocalyptic number.

It is an amenable number.

825561 is a deficient number, since it is larger than the sum of its proper divisors (522279).

825561 is a wasteful number, since it uses less digits than its factorization.

825561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 317 (or 314 counting only the distinct ones).

The product of its digits is 2400, while the sum is 27.

The square root of 825561 is about 908.6038740838. The cubic root of 825561 is about 93.8101267627.

The spelling of 825561 in words is "eight hundred twenty-five thousand, five hundred sixty-one".