820109582 has 4 divisors (see below), whose sum is σ = 1230164376. Its totient is φ = 410054790.

The previous prime is 820109581. The next prime is 820109611. The reversal of 820109582 is 285901028.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820109581) by changing a digit.

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 as a sum of consecutive naturals, namely, 205027394 + ... + 205027397.

It is an arithmetic number, because the mean of its divisors is an integer number (307541094).

Almost surely, 2^820109582 is an apocalyptic number.

820109582 is a deficient number, since it is larger than the sum of its proper divisors (410054794).

820109582 is a wasteful number, since it uses less digits than its factorization.

820109582 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 410054793.

The product of its (nonzero) digits is 11520, while the sum is 35.

The square root of 820109582 is about 28637.5554473492. Note that the first 3 decimals coincide. The cubic root of 820109582 is about 936.0318546334.

The spelling of 820109582 in words is "eight hundred twenty million, one hundred nine thousand, five hundred eighty-two".