825781780 has 12 divisors (see below), whose sum is σ = 1734141780. Its totient is φ = 330312704.

The previous prime is 825781771. The next prime is 825781787. The reversal of 825781780 is 87187528.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 651066256 + 174715524 = 25516^2 + 13218^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 825781780.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (825781787) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20644525 + ... + 20644564.

It is an arithmetic number, because the mean of its divisors is an integer number (144511815).

Almost surely, 2^825781780 is an apocalyptic number.

It is an amenable number.

825781780 is an abundant number, since it is smaller than the sum of its proper divisors (908360000).

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

825781780 is a wasteful number, since it uses less digits than its factorization.

825781780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41289098 (or 41289096 counting only the distinct ones).

The product of its (nonzero) digits is 250880, while the sum is 46.

The square root of 825781780 is about 28736.4190531806. The cubic root of 825781780 is about 938.1848857311.

The spelling of 825781780 in words is "eight hundred twenty-five million, seven hundred eighty-one thousand, seven hundred eighty".