820560390 has 128 divisors (see below), whose sum is σ = 2224115712. Its totient is φ = 192360960.

The previous prime is 820560383. The next prime is 820560401. The reversal of 820560390 is 93065028.

It is a happy number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 809524 + ... + 810536.

It is an arithmetic number, because the mean of its divisors is an integer number (17375904).

Almost surely, 2^820560390 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 820560390, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1112057856).

820560390 is an abundant number, since it is smaller than the sum of its proper divisors (1403555322).

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

820560390 is a wasteful number, since it uses less digits than its factorization.

820560390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1134.

The product of its (nonzero) digits is 12960, while the sum is 33.

The square root of 820560390 is about 28645.4252892150. The cubic root of 820560390 is about 936.2033330810.

The spelling of 820560390 in words is "eight hundred twenty million, five hundred sixty thousand, three hundred ninety".