820583257 has 8 divisors (see below), whose sum is σ = 887567240. Its totient is φ = 754151040.

The previous prime is 820583221. The next prime is 820583261. The reversal of 820583257 is 752385028.

820583257 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 4 ways, for example, as 457147161 + 363436096 = 21381^2 + 19064^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-820583257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (820583207) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 134844 + ... + 140797.

It is an arithmetic number, because the mean of its divisors is an integer number (110945905).

Almost surely, 2^820583257 is an apocalyptic number.

It is an amenable number.

820583257 is a deficient number, since it is larger than the sum of its proper divisors (66983983).

820583257 is a wasteful number, since it uses less digits than its factorization.

820583257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275883.

The product of its (nonzero) digits is 134400, while the sum is 40.

The square root of 820583257 is about 28645.8244252107. The cubic root of 820583257 is about 936.2120295616.

The spelling of 820583257 in words is "eight hundred twenty million, five hundred eighty-three thousand, two hundred fifty-seven".