820135625 has 20 divisors (see below), whose sum is σ = 1030198356. Its totient is φ = 652680000.

The previous prime is 820135609. The next prime is 820135639. The reversal of 820135625 is 526531028.

It can be written as a sum of positive squares in 10 ways, for example, as 173501584 + 646634041 = 13172^2 + 25429^2 .

It is not a de Polignac number, because 820135625 - 2⁴ = 820135609 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 820135591 and 820135600.

It is an unprimeable number.

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 19 ways as a sum of consecutive naturals, for example, 119795 + ... + 126455.

Almost surely, 2^820135625 is an apocalyptic number.

It is an amenable number.

820135625 is a deficient number, since it is larger than the sum of its proper divisors (210062731).

820135625 is an equidigital number, since it uses as much as digits as its factorization.

820135625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6878 (or 6863 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 32.

The square root of 820135625 is about 28638.0101438630. The cubic root of 820135625 is about 936.0417625856.

The spelling of 820135625 in words is "eight hundred twenty million, one hundred thirty-five thousand, six hundred twenty-five".