820909025 has 12 divisors (see below), whose sum is σ = 1034616444. Its totient is φ = 645960000.

The previous prime is 820909013. The next prime is 820909027. The reversal of 820909025 is 520909028.

820909025 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 6 ways, for example, as 169026001 + 651883024 = 13001^2 + 25532^2 .

It is not a de Polignac number, because 820909025 - 2⁴ = 820909009 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (820909027) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 267626 + ... + 270675.

It is an arithmetic number, because the mean of its divisors is an integer number (86218037).

Almost surely, 2^820909025 is an apocalyptic number.

It is an amenable number.

820909025 is a deficient number, since it is larger than the sum of its proper divisors (213707419).

820909025 is a wasteful number, since it uses less digits than its factorization.

820909025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 538372 (or 538367 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 35.

The square root of 820909025 is about 28651.5099951120. The cubic root of 820909025 is about 936.3359038779.

The spelling of 820909025 in words is "eight hundred twenty million, nine hundred nine thousand, twenty-five".