820582381 has 2 divisors, whose sum is σ = 820582382. Its totient is φ = 820582380.

The previous prime is 820582379. The next prime is 820582409. The reversal of 820582381 is 183285028.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 597558025 + 223024356 = 24445^2 + 14934^2 .

It is a cyclic number.

It is not a de Polignac number, because 820582381 - 2¹ = 820582379 is a prime.

It is a super-2 number, since 2×820582381² = 1346710888015258322, which contains 22 as substring.

Together with 820582379, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 820582381.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (820582351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410291190 + 410291191.

It is an arithmetic number, because the mean of its divisors is an integer number (410291191).

Almost surely, 2^820582381 is an apocalyptic number.

It is an amenable number.

820582381 is a deficient number, since it is larger than the sum of its proper divisors (1).

820582381 is an equidigital number, since it uses as much as digits as its factorization.

820582381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30720, while the sum is 37.

The square root of 820582381 is about 28645.8091350201. The cubic root of 820582381 is about 936.2116964157.

The spelling of 820582381 in words is "eight hundred twenty million, five hundred eighty-two thousand, three hundred eighty-one".