820620831 has 4 divisors (see below), whose sum is σ = 1094161112. Its totient is φ = 547080552.

The previous prime is 820620797. The next prime is 820620839. The reversal of 820620831 is 138026028.

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

It is not a de Polignac number, because 820620831 - 2⁶ = 820620767 is a prime.

It is a super-2 number, since 2×820620831² = 1346837096542261122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820620839) 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 in 3 ways as a sum of consecutive naturals, for example, 136770136 + ... + 136770141.

It is an arithmetic number, because the mean of its divisors is an integer number (273540278).

Almost surely, 2^820620831 is an apocalyptic number.

820620831 is a deficient number, since it is larger than the sum of its proper divisors (273540281).

820620831 is a wasteful number, since it uses less digits than its factorization.

820620831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 273540280.

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 820620831 is about 28646.4802549982. The cubic root of 820620831 is about 936.2263188669.

Adding to 820620831 its reverse (138026028), we get a palindrome (958646859).

The spelling of 820620831 in words is "eight hundred twenty million, six hundred twenty thousand, eight hundred thirty-one".