825640 has 16 divisors (see below), whose sum is σ = 1857780. Its totient is φ = 330240.

The previous prime is 825637. The next prime is 825647. The reversal of 825640 is 46528.

It can be written as a sum of positive squares in 2 ways, for example, as 770884 + 54756 = 878^2 + 234^2 .

It is not an unprimeable number, because it can be changed into a prime (825647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10281 + ... + 10360.

2⁸²⁵⁶⁴⁰ is an apocalyptic number.

It is an amenable number.

825640 is an abundant number, since it is smaller than the sum of its proper divisors (1032140).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

825640 is a wasteful number, since it uses less digits than its factorization.

825640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20652 (or 20648 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 825640 is about 908.6473463341. The cubic root of 825640 is about 93.8131189759.

It can be divided in two parts, 8 and 25640, that multiplied together give a triangular number (205120 = T₆₄₀).

The spelling of 825640 in words is "eight hundred twenty-five thousand, six hundred forty".